Sites I Recommend
Apace .htaccess file generator
Generate effective robots.txt files that help ensure Google and other search engines are crawling and indexing your site properly.
Top SEO Sites for Beginners
The Free Beginner's Guide to SEO provided SEOmoz.org has been read over 1 million times and provides the information you need to rank better.
Website Validators / Checkers
Search Engine Friendly Redirect Checker
Google PageRank Checkers:
Enter the URL you want to check and this tool displays PageRanks on top of all of the links on your website's page!
Helpful Web Development Resources
Learn .htaccess in 10 minutes | Softexpert Moldova