Want to know how search engines process URLs and Domain names?. Here is a video from Nathan Buggia from the Live Search Webmaster Center.

From the October Google Webmaster Chat Q &A:

Adrienne, San Francisco: For SEO, I'd like to improve my rankings by removing technical obstacles (starting with dynamic URL parameters), what are the most important site fixes to make and how can I document before and after success metrics using the Google Webmaster Tool?

JohnMu: To check the crawlability of your site, I would recommend crawling your site with a crawler like Xenu's Link Sleuth (freeware, for Windows). Doing that gives you a rough look at how search engines view your site and can point you towards areas where crawlers get stuck in a loop or start crawling duplicates based on the URL parameters.