Chameleon is my tool of choice. HIGHLY recommended.
Babagirl put together a great tutorial on how to get started using it.
http://www.babagirl.com/ChamSub/
She's got some links there, so feel free to support her work
I've been using Nova Submitter for the past few weeks and am QUITE IMPRESSED with the results so far. It's pretty easy to use too! They've got a FREE 2 week trial, so you've got nothing to lose in trying it out.
DOWNLOAD FREE 2 WEEK NOVA SUBMITTER TRIAL