video editing programs

in the next few months i plan on getting a GoPro hero 2 camera, and start filming once im in denver, stuff like mountain biking, snowboarding, and hiking.
the stuff that is produced on this board blows my mind, clearly some very talented people here.
my question is what program is best for video editing? i dont need top of the line stuff, just intro level programs.
i have a macbook pro, which has iMovie on it, but i have never used it. is that a program that would work for what im looking for?
also do most of these programs come with tutorials?
Thanks