Having used FCP, Vegas, iMovie, and a little bit of other systems, I don't think fancy editing software is all that necessary. If you're just starting out, iMovie is not a bad idea as you can quickly get into the fundamentals. Cut and dissolve.
These are the basic editing functions and all the NLEs give the same end results here.
iMovie is not a bad way of learning the fundamentals and it is very easy to get into. *Disclaimer: I haven't used iMovie recently so I don't know how well it handles the latest formats. And when I did use iMovie, it would crash and take out half your project if it was too big. Some these are some things to watch out for.
Anyways, I wouldn't count it out because it's so easy to use and is a good way to learn the fundamentals. I also think they took out the cheesy effects which are prone to abuse (you know those videos where they throw in every effect that comes with the program...). I haven't seen anything on the PC side that is as easy to use as iMovie.
