http://office.microsoft.com/en-us/templates/CT101172561033.aspx (Choose your letter and Click Download Now. Click Continue.
Click Download Now. Click Save. Rename the file name so that it is the same as the Microsoft letter name. Once you do your
first download, options will change. The next time you will click Download Now for the next two screens. Rename the file name
to the name of the letter. Click SAVE.)

http://www.4hb.com/letters/
http://www.writinghelp-central.com/sample-letters-business.html
http://www.writinghelp-central.com/sample-letters-personal.html
http://www.insiderreports.com/resources/library/searchletters.asp
http://www.quintcareers.com/cover_letter_samples.html
http://jobsearch.about.com/od/referenceletters/Sample_Reference_Letters.htm
http://www.bestcoverletters.com/
http://www.career.vt.edu/JOBSEARC/coversamples.htm