Can I put my sitemap only on the index page? Or do I have to put it on every page of my site?
To which type of sitemap are you referring – an HTML webpage which helps users locate content on your site by organizing it, or an XML document which helps search engines find all the documents available on your website?
If it’s the first, you don’t have to put one anywhere. It’s just a normal webpage.
If it’s the second, then it is not “on” any page of your site, it is just a document sitting at some web-accessible URL. You can use facilities provided by the major search engines to tell them where to find your sitemap, or provide the sitemap location through a Sitemap: directive in a robots.txt file at the root of the domain.
Hiya, hope the sitemap itself is a web page which is inter connected with each pages of the website. Sitemap will normally help the search engines to crawl each page of the website.
Once you create your sitemap, you can upload it to your Google Webmaster Tools account. Your sitemap is a map of all of the web pages connecting your site, so you don’t need to place it on any of your pages.
With an HTML sitemap you should link it into all the pages where people might enter your site. If it is only on the home page then people entering through any other page will not know it is there.
What do you mean “upload it to your Google Webmaster Tools account”?
The sitemap file is stored on your webserver. All you do in Webmaster Tools is tell Google where that file is located. Nothing is “uploaded” to Google.
its up… and since homepage crawl first usually crawl first its fine if you just put on your index page…
It is good idea to put it on every page. I usually put it in footer of site.
I don’t think site map is really necessary for each and every page, but if you have a site with perfect navigation with in the website then its really helpful for both the crawler to crawl and also the users too. 
Since the purpose of a sitemap is to allow people to find the page they are looking for when they get lost on your site the sitemap link needs to be on any page where those people can get to that isn’t what they were looking for where there isn’t a direct link to the page they want.
You can provide a link in your index page alone. but If your site contains many pages it is better to provide a link for ur sitemap in the footer of every page .
I think that depends on the size/complexity of the site. In someways a sitemap may confuse a visitor even more.