Here are some places to find viable candidates with proven experience in writing for a variety of different markets. You'll also find ways to use "canned" copy in your printed material for free.

All Freelance Work
Browse freelancers by category or post a job here.

ClipCopy
Offers "canned" content on a variety of subjects for free. 

eLance
A global marketplace for freelance writing, editing, and marketing communications services. 

Freelance Work Exchange
Here are hundreds of links to potential writers for your next project.

Freelance Writing
Post a description of the type of writer(s) you're looking for, and freelancers will contact you directly.

Home Run Connection
A great resource for linking independent businesses with business.

JobList
A nationwide talent pool.

Solo Gig
They market the talents of experienced freelancers, consultants and independent professionals to employers nationwide.

Workaholics 4 Hire
They offer a full range of services to suit your hiring needs. Whether you're looking for onsite, offsite, permanent, contract, long term or short term, they work with you to find the right solution for your needs. 

Writer Find
Find quailty writers for your corporate communications, copywriting, or public relations needs, as well as columnists, editors, proofreaders, ghostwriters, researchers, technical writers, instructional writers, authors, and creative writers.

Xchange Team
They work with thousands of talented freelance consultants from junior executive to board director level and will match you with the best person to meet your needs.