How to Become a Freelance Writer
from various contributors at wikiHow

Seven Tips for Becoming a Full-Time Freelance Writer
from Dwight Arvin at EzineArticles

How to Score the Guest Posts That Will Get Your Freelance Blog Noticed
from Carol Tice at FreelanceSwitch

What Freelancers Really Need to Know About Testimonials
50+ Myths About Freelancing
from Laura Spencer at

Your Self-Supporting Hobby: Some Resources for Freelance Writing
from Julia M. Reffner at The Writers Alley

Bonus Resources:

Freelancer’s Survival Guide
from Kristine Kathryn Rusch

15 Killer Resources for Beginning Freelance Writers
from Larry at

Guide to Freelancing (collection of freelancing articles)

Bonus Anecdote:
I Gave Up My Job Security to Try Freelance Writing Full-Time — And After a Terrifying Start It’s Worked Out Great
from Lindsay Cross at xoJane