Question regarding book for low limit intermediate-beginner?

[gezuz]

Hey all, first post here =/. Anyways, I read over the essay regarding the stages of a poker player's life on 2+2, and how he progresses from tight passive to loose aggressive. I believe this is where I am in my game, being loose aggressive, but am looking for some help in moving to the next stage. I 4 table 1/2, but have a winning record at 3/6. I've heard SSHE recommended, and plan on getting a copy of that, but I'm wondering if anyone is in or has been in my position, and what helped them improve their game. Mainly I'm looking for books to suggest a more focused aggression, and where to raise preflop and postflop at.

Thanks!