Need a review of basic grammar rules? These sites will help build your knowledge of grammar.
Grammar Book
Grammar Girl
Chomp Chomp (Interactive grammar reviews)
Grammar Gold (very basic grammar rules)
OWL at Purdue- Writing the Basic Business Letter
OWL at Purdue- Cover Letter Workshop
Etiquette Rules for Writing Business Emails
Damn Good Resume
Resume Tips and Tricks
The Only Resume Advice You'll Ever Need