You might not expect it, but the URLs of your content can actually make a big difference as to how the search engines index your site. Search engine friendly URLs use keywords from your content inside the URL itself. That gives you a better chance of inching up higher on the search engine results pages.
Many sites, particularly ones whose content is fed from a database, operate with dynamic URLs. This is a URL that specifies a page and passes parameters to identify which content should be shown. The problem with this kind of URL is that it doesn’t index very well. Dynamic URLs look something like this:
As you can see, the dynamic URL calls a generic file, and passes parameters to load the content. You’re much better off with a URL such as the following, which includes valuable keywords that appear in the content AND the URL:
When you’re ready to change over to search engine friendly URLs, you need to make sure the old dynamic ones are no longer visible or you risk receiving a duplicate content penalty. Either use a 404 to kill the old links, or – preferably – a 301 redirect to help the search engines find the new URLs.
There is one more thing you need to be careful about with your URLs: whether or not they end in a slash. Believe it or not, that makes a world of difference to a search engine. If you choose to use slashes at the end of your URLs, do the same thing with all your pages. If a search engine sees two identical URLs, one with a slash and one without, it will index both of them and assume they are duplicate content. This is especially true with home page URLs.
Now I’d like to move on to sitemaps. Sitemaps are a valuable tool which allows you to more thoroughly index your web site. There are two kinds of sitemaps: search engine submitted sitemaps and hosted sitemaps. The first kind is a special file you put together and submit to a search engine in the hope that the engine will process it and index all of the pages in the map. Google, Yahoo, and MSN are known to have specific formats for sitemaps; in fact, these big three have joined forces in an open sitemap initiative, about which you can find more information at sitemaps.org.
A hosted sitemap is an HTML page on your web site that links to all the content that you would like to have indexed by the search engines. At one time it was common practice to link to an archive, or more “search engine friendly” copy of the content, so the search engine would have an easier time locating the relevant parts of your page. If you use this type of sitemap, it must contain ONLY the links to the actual content and not two versions of the same content – in other words, you do not want to have one page for your visitors and another page for the search engines. Since many popular forum packages come equipped with this archiving functionality, you need to be aware of it; otherwise, you could face possible duplicate content penalties.
Search Optimization 
