Thumbnail gallery for a newb

After cleaning up my pages a few bugs disappeared, well impressed with those validator tools. The only problem i feel i have at this stage now is, the more text i add in the paragraphs under each gallery item it pushes the thumbnail below it down the page. Should the overflow: scroll deal with this?

Thanks in advance.

Daz

HTML for my thumbnail test page.

<!DOCTYPE html>
<html lang="en">

<head>
    <title> Fitted Kitchen Specialist </title>
    <meta charset="utf-8" />
    <link href="kitchen1.css" rel="stylesheet" type="text/css" />
</head>

<body>
    <div id="header">
        <div id="sitebranding">
            <h1> FittedkitchenSpecialist.com</h1>
        </div>
        <!--end of sitebranding div-->
        <div id="tagline">
            <p> Fitted kitchen specialist in the Nottingham area. </p>
        </div>
        <!--end of tagline div-->
    </div>
    <!--end of header div-->
    <div id="navigation">
        <ul>
            <li><a href="kitchen.html">Home</a></li>
            <li><a href="kitchen%20about.html">About</a></li>
            <li><a href="Kitchen%20gallery.html">Image Gallery</a></li>
            <li><a href="Kitchen%20thumbs.html">Thumbs Gallery</a></li>
            <li><a href="Kitchen%20test.html">Test</a></li>
            <li><a href="kitchen%20contact.html">Contact</a></li>
            <li><a href="Kitchen%20quotes.html">Words On Life</a></li>
        </ul>
    </div>
    <!-- end of navigation div -->
    <div class="container">
        <h2>Welcome to my virtual showroom</h2>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Ebony%20tundra.jpg">"><img src="kitchen%20thumbs/Avant%20Ebony%20tundra%20Small.jpg" alt="High gloss door in Ebony colour."/></a>
            <h3>Avant Ebony</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Ebony%20tundra.jpg">"><img src="kitchen%20thumbs/Avant%20Ebony%20tundra%20Small.jpg" alt="High gloss door in Ebony colour."/></a>
            <h3>Avant Ebony</h3>
            <p>High gloss vinyl 18mm MDF..</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <div class="galleryItem">
            <a href="kitchen%20thumbs/Avant%20Alabaster.jpg">"><img src="kitchen%20thumbs/Avant%20Alabaster%20Small.jpg" alt="High gloss door in Alabaster colour."/></a>
            <h3>Avant Alabaster</h3>
            <p>High gloss vinyl 18mm MDF.</p>
        </div>
        <!--end of gallery item div-->
    </div>
    <!--end of container div-->
</body>

</html>

CSS:

body {
            font-family: Verdana, Helvetica, Arial, sans-serif;
            background-color: #E4EEFF;
            line-height: 125%;
            padding: 0;
            border: 0;
        }
        
        h1,
        h2,
        h3 {
            font-family: "Trebuchet MS", Helvetica, Arial, sans-serif;
        }
        
        h1 {
            font-size: x-large;
            background-color: #6d92d8;
            color: white;
            font-weight: bold;
            padding-top: 2em;
            padding-bottom: .9em;
            padding-left: .4em;
            margin: 0;
            background: #6d92d8 url(backgrounds/worktop-small.jpg) repeat-y right;
        }
        
        h2 {
            color: navy;
            font-size: 130%;
            font-weight: normal;
            padding-top: 15px;
        }
        
        li {
            font-size: small;
            list-style-type: square;
        }
        /* circle, disc, square and none options,
     read CSS anthology by Rachael Andrew for more detail on button styling*/
        
        p {
            font-size: small;
            color: navy;
        }
        /* Hashtag denotes an ID */
        
        #tagline P {
            font-style: italic;
            font-family: Georgia, Times, serif;
            background-color: #bed8f3;
            border-top: 3px solid #7da5d8;
            border-bottom: 3px solid #7da5d8;
            padding-top: .2em;
            padding-bottom: .4em;
            padding-left: .8em;
            margin: 0;
            background: #bed8f3 url(backgrounds/tagline-fade.jpg) repeat-y right;
        }
        
        #navigation {
            width: 180px;
            height: 484px;
            background: #7da5d8 url(backgrounds/drawer2.jpg) no-repeat;
            /*must use backgrounds as source folder*/
            background-color: #bed8f3;
            color: #6d92d8;
            /* colours bullet points only as visited/hover/active are controlled lower down*/
        }
        
        #header {
            border-top: 3px solid #7da5d8;
        }
        
        em {
            text-transform: uppercase;
        }
        
        a {
            font-weight: bolder;
            color: black;
        }
        
        a:link {
            color: orange;
            /* colours email address  only*/
        }
        
        a:visited {
            color: white;
        }
        
        a:hover {
            text-decoration: none;
            color: white;
            background-color: navy;
        }
        
        a:active {
            color: green;
            background-color: navy;
        }
        
        .fun {
            color: #339999;
            font-family: Georgia, Times, serif;
            letter-spacing: 0.05em;
        }
        
        .fun p {
            color: green;
        }
        
        cite {
            color: navy;
            font-weight: bold;
        }
        
        h2,
        ul {
            margin-top: 15px;
        }
        /*This section deals with the position of items on the screen.
         It uses absolute positioning - fixed x and y coordinates measured
         from the top-left corner of the browser's content display.*/
        
        #navigation,
        #bodycontent,
        #header {
            position: absolute;
        }
        
        #navigation,
        #bodycontent {
            top: 115px;
            /* 104% will show border across top of navigation box 101% will merge*/
        }
        
        #bodycontent {
            left: 200px;
        }
        
        #header,
        #tagline {
            width: 100%;
        }
        /*#navigation {
         position: relative;
          left: 1300px;
         }
         An example of how to move navigation across to right*/
        
        .feature {
            float: right;
            margin: 10px;
        }
        
        .galleryphoto img {
            border: 15px solid white;
        }
        
        .galleryphoto p {
            font-size: 65%;
            font-weight: bold;
            margin-top: 0;
            width: 430px;
            line-height: 1.4em;
        }
        
        .galleryphoto p span {
            font-weight: normal;
            color: gray;
        }
        /*Alternative to the above
.photocredit {
    font-weight: normal;
    color: gray;
}*/
        
        .galleryphoto {
            padding-bottom: 10px;
            border-bottom: 1px solid navy;
            margin-bottom: 10px;
        }
        /* test for thumbnails gallery*/
        
        .container {
            position: absolute;
            width: 80%;
            margin: 150px;
            overflow: auto;
            float: right;
        }
        
        .container {
            left: 80px;
        }
        
        .galleryItem {
            color: grey;
            font: 10px/1.5 Verdana, Helvetica, sans-serif;
            float: left;
            width: 16%;
            margin: 2% 2% 50px 2%;
        }
        
        .galleryItem h3 {
            text-transform: uppercase;
            text-align: center;
        }
        
        .galleryItem img {
            -webkit-border-radius: 5px;
            -moz-border-radius: 5px;
            border-radius: 5px;
            max-width: 100%;
        }
        
        .galleryItem p {
            text-align: left;
        }
        /*.galleryItem 
    border: 5px solid white;
    */
        /* MEDIA QUERIES*/
@media only screen and (max-width : 940px),
only screen and (max-device-width : 940px){
    .galleryItem {width: 21%;}
}

@media only screen and (max-width : 720px),
only screen and (max-device-width : 720px){
    .galleryItem {width: 29.33333%;}
}

@media only screen and (max-width : 530px),
only screen and (max-device-width : 530px){
    .galleryItem {width: 46%;}
}

@media only screen and (max-width : 320px),
only screen and (max-device-width : 320px){
    .galleryItem {width: 96%;}
    .galleryItem img {width: 96%;}
    .galleryItem h3 {font-size: 18px;}
    .galleryItem p {font-size: 18px;}
}