For now download...

https://addons.mozilla.org/en-US/firefox/addon/2007 This shows you pagerank for the current page

https://addons.mozilla.org/en-US/firefox/addon/60 This allows you to "turn off" certain aspects of teh page, as well as highlight certain page components

https://addons.mozilla.org/en-US/firefox/addon/3036 Download this, but don't turn it on for now. I will go over it tomorrow.

http://tools.compete.com/ This shows you est. visitor number as well as some other figures.

siteexplorer.search.yahoo.com

Some Interesting and Useful Links

http://www.vaughns-1-pagers.com/internet/google-ranking-factors.htm

http://www.searchenginejournal.com/7-essential-seo-cheat-sheets/8908/

http://searchenginewatch.com/ (check out the forums, here lots of SEO marketers both amateur and professional chat about ranking factors.)

http://www.seomoz.org/ugc/seo-myths-that-persist-keyword-density

http://www.bluehatseo.com/ (this guy has some very original SEO techniques)

http://www.digeratimarketing.co.uk/2008/06/12/blackhat-seo-tools-scripts-the-digerati-blackbox/

http://www.clickz.com/3625355

http://www.metamend.com/seo.html

http://www.seomoz.org/article/search-ranking-factors#f46

Tools

http://www.furtheronline.co.uk/tools.aspx

http://tools.seobook.com/

http://www.smashingmagazine.com/2006/09/22/complete-list-of-best-seo-tools/

http://www.linkvoodoo.com/

http://www.seochat.com/seo-tools/