You're probably going to get a different answer from everybody. :)

When I first started, I concentrated mostly on learning songs. Just chords at first and then gradually moving into leads. I only learned enough basic theory to get me by. (like what an E chord was)
It depends on your own preference really and what you intend to do once you learn how to play.
If playing in garage bands is your main goal, then learning as many songs and licks and tricks as possible might be the way to go.
If you intend on doing studio work or need to communicate your ideas to other people, or just simply want to be able to sight read.. then starting with theory might be more beneficial.

You could also do a bit of compromising. Spend a month learning songs and leads. Then spend the next month just sticking to theory.
Then go back the month after that and see how the theory applies to the songs you've already learned.