you need to decide what kind of music you want to play, what style, finger or pick. Start with simple chord songs and move on to harder stuff when you have learned them. Learn your major,minor,7ths,9ths. augmented and diminished chords. With those you can play just about anything. Practice playing each note of a chord til you get a feel for the musical structure of the chords, each type of chord has the same stucture ie 135 for major,1b35 for minor etc. Then play the notes around the chords to hear how they fit against the notes in the chord. A good way to do this is to record a simple slow 3 chord blues and jam over it.
Once you are comfortable with bar chords and can play some tunes, I highly recomend buying Kirks
Plane Talk book and DVD. It is not for absolute beginners so wait til you have some playing time under your belt first. I went from not being able to jam to feeling comfortable jamming over almost anything in just 8 months and I am a slow learner.
hope that helps.