What to charge?

Hello everyone,

As a preface, I'm very new to the world of Freelance, and fairly new in general to a lot of post-production elements (read: Novice) except for Editing (which I'm fairly well versed in). I was curious if there is a resource out in cyberspace or if you fellow COW's have any advice on determining what one who lacks in experience should charge for various tasks. I realize that there's no real set-standard, but a place to start would help.

Lacking professional experience in most areas except editing, I obviously shouldn't expect to charge a professional rate for, say, rotoscoping or keying, but I am knowledgeable in those tasks and would like to be paid for work I do. Like I said though, I'm unaware of any baseline to start from. =/

Also, should one charge by the hour for everything? Should I set a specific price for different tasks? Does one estimate how many hours the overall job would take and charge a fee based around that?

Specifically, I'm curious about pricing for Editing footage (I haven't done freelance, I'm currently an in-house editor for a production company), Rotoscoping, Keying/Greenscreen, Footage cleanup and Line-Removal.

I'm sorry if this post is A. Long-winded or B. Confusing, but again, any help or constructive responses will be appreciated.