I'd recommend learning minor pentatonic and the aeolian mode (aka the minor scale) for that style music. Lead guitar is playing a melody over rhythm basically, only it's usually very complex compared to something like a vocal melody. The most important thing about it is phrasing, how you say what you say. A good guitarist knows which notes to use to get a point across, and uses no more and no less than what he/she needs. Then again, you can impress a lot of people just by playing notes that are in key really really fast, but just know what notes fit over the rhythm, and use them however you feel. Thats pretty good advice i think. Just do whatever you feel.

Atomic