Shorty -
Cover Letters, if properly written, are in invitation for employers, recruiters, etc. to read your resume. Resumes support what is revealed in cover letters.
A properly written cover letter identifies the exact being sought, highlights 3-5 notable accomplishments, and includes contact information.
Use Free-Resume-Builder.net's (http://www.free-resume-builder.net) free online resume and career letter builder tool to build your resume.
Good luck.