Honestly, when I started out, I used both.I would start off for the first month with just the book so you learn basic chords and all that good stuff. Then, once you get comfortbale with it, go on to tabs. If you hear a song that you want to learn, go ahead a learn it (You can go to Ultimate-guitar.com for tabs). Even if the song is too hard for you, at least you try and when you get better, then go back to the song.

Now when it comes to memorizing...I never really had a problem with it. When you learn a song, just practice it everyday until you have it down perfect. If you start forgetting, then just go back to the tabs for a review. I don't think you'll have a problem with it as long as you get the tab down perfect.

But yeah, when you do get the money, I would look into lessons. It's always good to have someone there to help you out and guide you through. Good luck with everything, and most important...Just have fun and enjoy!