Learn to play other band's solos note for note. This will help you build up a good collection of techniques that you can put together to form your own solos eventually. Honestly, I think that's why I'm not good at lead guitar is because I haven't done that. I know scales, I know positions, but that doesn't help make "music". Learning from examples and knowing what kind of patterns sound good will help you tremendously.
Definitely learn scales, but don't just focus on scales. Learn some solos exactly, then change them up a bit to put your own spin on it. Do this enough and you'll have a lot of stuff to pull from when it comes time to improvise a wicked solo.
Now if only I can take my own advice.
-tkr