webseotalk.com

All major search engines have guidelines to help get the best possible placing for your site:

Google Information for Webmasters -> http://www.google.com/webmasters/guidelines.html
Yahoo! Guidelines on Spam -> http://help.yahoo.com/help/us/ysearch/deletions/deletions-05.html
MSN Guidelines for successful indexing -> http://search.msn.com/docs/siteowner.aspx?t=SEARCH_WEBMASTER_REF_GuidelinesforOptimizingSite.htm
Teoma Tech Information (for Ask) -> http://sp.ask.com/docs/about/aj/teoma.htm

Few more links that will help you

Google

Google Support on 301s and domain.com & http://www.domain.com
http://www.google.com/support/bin/answer.py?answer=3875

Google Support on changing a URL
http://www.google.com/support/bin/answe ... &topic=363

Google Changing Host
http://www.google.com/support/bin/answe ... &topic=363

Google Information for Webmasters how to choose an SEO
http://www.google.com/webmasters/seo.html

Yahoo

Yahoo Content Quality Guidelines
http://help.yahoo.com/help/us/ysearch/b ... cs-18.html

MSN

MSN Guidelines for successful indexing
http://search.msn.com/docs/siteowner.as ... ngSite.htm