As a faithful member of Gamespot, I feel it is my duty to assist those in need, particuarly those on this forum, who are often asking perfectly legitimate questions about Epic Mickey 2 - believe me, I was as confused as you were when I first got the game!
With this in mind, I have decided to, much like I did with EM1, produce a video walkthrough of EM2. In it, I will be covering everything required for the good 'ending' as well as locating most of the pins and having a bit of a rant about how the game was produced, 'tested' (in massive sarcasm quotes) and, ultimately, truncated. The first video can be found here: http://www.youtube.com/watch?v=kC2Enh3V7f0&list=PLc9URPMS0fNB0WHovKFLNyPkTHlPw6gvN&index=1
I've also attempted to inject a mild dose of humour into the playthrough to make the whole experience at least vaguely entertaining. I hope you enjoy it.
I hope that the walkthrough will cover most of the questions everybody poses to me, but, as always, do not hesitate to ask about the game here and we'll do our best to help you.