|IzzyVideo's free tutorials will help with using FCProX!|
IzzyVideo FCPX video tutorials
(or you can spend £30+ on books!)
I've copied in the full list below. Here's an Amazon link for books on Final Cut Pro X - make sure its for an up to date version.
I'll be adding some tips here. There is also a Final Cut tag on this blog.
Here's a short vodcast on using the green screen tool: