[Bruno Schalch]

I wouldn’t start with FCPX, I think it is closer to imovie than to a professional and robust editor so it becomes something like imovie pro. Media composer and premiere, on the other side, are getting better and better(CS6 was recently released for premiere and if you use after effects frecuently you could take advantage of dynamic link).
I would start with premiere or media composer, but not with final cut Pro X.