I would totally suggest more jamming with your friends for starters! there's nothing like it.
I would stay well clear of Tab if I were you. It's only ever used in guitar magazines to appeal to the masses, and you'll never find yourself in a professional situation (or at least I haven't in the past 12 years) needing to read tab.
I would jam along to your favorite records, try and get some basic music theory together to where you can notate some music, and then write down all the ideas you can from records you're listening to. Transcribing any kind of music like this will develop your ear, your time, your technique, and will also give you a library of written ideas that you can refer back to at any time for inspiration.
Easy,
Janek