My advice would be, get a good editing program (Final Cut or Premier; a friend of mine used Vegas in College, but I don't know anything about it except that it's cheap and my friend did some pretty cool stuff with it back in 2005)... editing is like any technical art, the more powerful and diverse your tools, the freer you'll be to pursue the art aspect of your endeavor.
Once you get your editing program, play around with it, learn the basic tools, your razor-blades, your rolling edits... practice making L and J cuts; maybe cut to music to get a basic handle on pacing and tempo (editing is a lot like being a musician)... Final Cut and Premier are pretty user friendly.
But these are your tool-sets, if you don't have the vision, you're not going to get anywhere... the best way to learn how to edit is by watching movies. Like writers reading, or musicians listening to music... watch your favorite films with an eye on the cuts, be attentive, see how different editors cut dialogue and action; pay attention to when editors hold on shots, and when they bombard you with images, and analyze why and what it does to the tone, pacing, and tempo of the film, how it manipulates emotions... in other words, look for the tiny brush-strokes in the painting.