Here are some sites that are helpful in explaining search engines, meta tags, and the like:

How Search Engines Work:

A list of search engine related information from UC Berkeley: http://www.lib.berkeley.edu/TeachingLib/Guides/Internet/FindInfo.html

If you are going to optimize your web site(s) yourself, a key element is targeting the right keywords - which you'd want to include in the title, Meta tags and content of the site. The best way to track these down is a paid tool called WordTracker (http://www.wordtracker.com). It's not expensive and you can buy the rights to their database by the day, week, month, etc.

One tool to measure how your site ranks against others in terms of link popularity is found at http://www.marketleap.com/publinkpop/. You could also download the Google Toolbar and measure Google's PageRank of any page you want at http://toolbar.google.com.

For general search engine and SEO information, a great site is Search Engine Watch, http://www.searchenginewatch.com.