Jazz Guitar

Where do I start for Jazz guitar?
Im really interested in learning to play jazz on guitar.I have a good grasp on the instrument already but I dont know where to start.Im currently learning common chords used in jazz but have no idea where to go after that.Its hard to improv a song with no bass line or drums or something so im kinda lost,any suggestions?
I would say get a jazz guitar method book..I have a great one I bought a few years back. It helped a lot. Also, learn the scales like the other guy said. The method book helps with that. The book I have is the Hal Leonard Jazz Guitar Method. Great book. Gives you theory, chord alterations, progressions and solo tips. It comes with a cd with play along tracks as well. Another great way to learn jazz is just to play along with some jazz albums.
Fingerstyle Jazz Guitar Improv – Jody Fisher