Guitar Help: Intermediate Books/Lessons?

[RunDownHouse]

I'm hoping someone can help me with this, because I'm a bit lost and all Google turns up is dubious products trying to get me to subscribe and whatnot.

I played guitar for a few years somewhat casually. I haven't played much for the last 2-4 years because I just haven't had time, but I want to start making time. I think I'm at an intermediate level: I can handle the rhythm parts for most Metallica stuff (for example), do an ok job at classical pieces as long as the fingerpicking pattern isn't toooo complicated, can play a good number of the selections in this book, etc. I'm pretty weak when it comes to lead/solo stuff, music theory (although I know a bit there), improv, etc. I think I've got the most basic parts of playing down, but don't know where to go from there.

So I'm looking for recommendations on good intermediate books to teach some of the theory behind leads/solos and improvs, exercises to improve things like speed, and so on. I'm also looking for advice on just what I need to learn next.

I don't think I really want to pay for private lessons at this point, although I took them when I first started.

Any help is appreciated, and sorry for no hot chick, since I'm at work.