I'm hoping to clear up this question that I see on a lot of unanswered forum posts: what width and height should I design my webpage to be? Rather than go into the science and technicalities of this answer, I will simply tell you how it's done, and you'll have to take my word for it. My resources for this answer are 10 years of web design and programming experience, and information taken directly from various SitePoint published web design books that my family and friends have acquired over the years. Yes, I'm not just a designer and developer myself, I am surrounded by similar people.
The truth is, the width should always be a certain percentage of the screen, while the height should always be variable, depending on the content. However, ALL OF THE MOST IMPORTANT INFORMATION should be ABOVE the fold - meaning all of the most vital information should be above the scrolling point on a webpage. So brief descriptions of content or titles, teaser quotes, etc. should be above the fold to summarize the content and catch the users attention so they... you guessed it, scroll down.
About scrolling - horizontal scrolling is a big no-no. Now most of the Site Point publications will tell you that the standard width to design for is 960px, which is derived from the browser width of the most common screen resolution of 2012 - 1024x768. HOWEVER, I have found it is best to incorporate a fluid page design, meaning if the resolution is much larger, like 1920x1280, the width will still be appropriately proportioned.
How to do this? Well, instead of creating images for tables using width percentages, and then discovering they are pixelated as they upsize to a larger browsers, you can try a couple things. Substitute as many graphics as possible for CSS. This is fail-proof, however designs may become simpler.
Simpler is not a bad thing at all. Check out Dawg House Design Studios - extremely simple page, and it is fluid to fit any display size. In fact, it is a special kind of fluid design called a Responsive Design, and you can find out more about this on websites like A List Apart, and in books like The Principles of Beautiful Web Design, by Jason Beaird. I believe he talks about responsive design starting in the second edition.
However, if this becomes too complicated, another easy way to design a fluid width, and psuedo-responsive design is to put your CPU and RAM to the test. What I mean by this is design the site at a 1920x1080 resolution at something like 250-300dpi, and have the browser scale it down based on screen resolution. This means that at 1024, the website width will be 93.75%, or 960px, while at 1920, the width will be 1800px. This means that it will be appropriately proportioned, without scrolling, every time, and you will never run into pixelated web pages.
The major benefit of a fully-responsive design is that it will change the entire layout depending on the resolution, meaning it is mobile friendly.
One thing I would definitely advise AGAINST is anything Word Press. But that is a discussion for a separate post. I did not proof-read this, take it as-is.