I have listed some of the SEO tools, hopefully it will help you

whois report

http://www.domaintools.com/

w3C validation checker

http://www.validator.w3.org

Broken link checker

http://www.dead-links.com/

Back Link Checker

http://www.backlinkwatch.com

Link Popularity Checker

http://www.webmaster-toolkit.com/link-popularity-checker.shtml

For html Validation

http://validator.w3.org/checklink

Keyword Research

https://adwords.google.com/select/KeywordToolExternal

http://freekeywords.wordtracker.com/

http://tools.seobook.com/keyword-tools/seobook/

http://www.keyworddiscovery.com/search.html

Search Engine Position Checker

http://www.seochat.com/

Sitemap Creator

http://www.xml-sitemaps.com/

http://www.sitemapbuilder.net/

http://tools.webmasters.sk/sitemap-creator.php