IMPROVISATION
A top concern of guitarists in all styles and at all skill levels is how to improvise. Those who cannot want to learn how this mysterious process works, and those who can want to improvise better.
Before you do another thing, read my review of Jamey Aebersold's DVD and book / CD set "JAZZ: Anyone Can Improvise!" It will change your life!
If you want to learn some great solo lines and experience improvising over real changes, check out Robert Conti's Ticket To Improv DVD's. You are learning from one of the best with these.
Easy Soloing for Jazz Guitar is a good introduction to jazz soloing for rock / blues players, or for beginning improvisers, although real beginners will want to work through it with a good teacher.
Are you struggling with the transition from strumming simple chords to something more musical? If so, check out Guitar Groove: A Session with Brooks Williams.
FINGERPICKING
Want to get rid of your pick and use your fingers like your guitar heroes do? I know of no better place to start than Mark Hanson's terrific book Contemporary Travis Picking. It is actually more of the first part of a 2-book series that continues into The Art of Solo Fingerpicking. Get both books to move from 0-60 in, well, 2 books.
REPERTOIRE
Do yourself a favour and add some songs that you will love to play and your audience will love to hear. A great place to start is Adam Rafferty's wonderful DVD How to Play the Music of STEVIE WONDER.