You are 1150? This means that a lot of the things suggested here will be of almost no use to you. Anything by Dvoretsky is going to be miles over your head. Once you become an A-class player, say 2000+, these materials will be very valuable.
Until then, there are many things you should do.
1) Don't get caught up in opening study. This simply won't do anything for you right now - your opponents don't know any opening theory, and therefore whatever you learn will be close to a complete waste.
2) TACTICS! Most games you win at this level will be because of tactics. They are ESSENTIAL. Get the manual of combinations vols. 1 and 2 from Convekta
www.convekta.com CT-art 3.0 is also very good but will probably not be useful until after the completion of volume one of the manual of combinations. Solve all of them in volume one and then move on to volume two. Also Reinfeld's 1001 Winning Chess Sacrafices and Combinations and Patnufieffs The Art of Combinations is very good. Reinfelds book is very good for beginners and should probably be used before moving on to volume two of the manual of combinations.
3) Studying the actual games: Right now it is very important to understand what was happening in chess 150 years ago for you. If you look at current grandmaster games, you may be entertained, but you will probably have no idea going on [I feel this way often and many here would call me a strong player at 2350!]. Get a collection of the games of Paul Morphy and analyse them.
4) Analysing your own play. This is the key to becoming a strong player. Look at the games you played and analyse them (especially your losses). Where did you go wrong? How did you lose?
Also I forgot to put it in the list, but learn basic endgame play. Do you know what the Lucena position is? Can you checkmate with two bishops and a king against a lone king or a knight and bishop against a lone king? Get an elementary endgame book. Dvoretsky's Endgame Manual was suggested earlier, but you need something much more down to earth for your level.
6) Once you feel like you understand how Morphy played and you feel as if you have a decent grasp of tactical concepts - i.e. you can solve easy problems (forced mate in 5, get decisive position in 3) you should be introduced to modern play. This will come from the most instructive chess book ever written, Aron Nimzowitsches My System.
Good luck in your quest for chess glory. Remember the most important thing is constant effort put into the game. It is much better to put in a half hour every day of the week than to put in a two hour session and a one and a half hour session on two seperate days of the week.
Good luck.