PR and BackLink Checker (Good) / Back-link Checker with PR 

SERP Check / Keyword Position Checker  / SERP Check / Free SEO Tools 

Link Search by keyword & PR / Fagan Finder /

KEYWORD DENSITY

Overture Keyword Research Tool / Google Keyword Research Tools

ROR Sitemap Generator / XML Sitmap Generator

Copyscape / Directory List / Get Indexed Fast / Directory Submission / ISEDN Search Engine & Web Directory

Google Adword Tools / View Overture Bids / SE Spider Simulator / Spider Simulator 

Tutorial

http://bugclub.org/beginners/internet/