For the opening something like FCO by GM van der Sterren or "Understanding chess openings" by IM Sam Collins is a good start. In these book you can find all you need now to play an opening. Later you'll want to have more detailled works.
A workbook with tactics is always good. Work with it 15 minutes every day.
For understanding chess better i would recommand studying annoted games. Maybe you could start with Alekhine:
http://www.russell-enterprises.com/mbgalek.html
http://www.russell-enterprises.com/ny1924.html
http://www.russell-enterprises.com/ny1927.html
http://www.russell-enterprises.com/nottingham1936.html
You also need to know some basics in the endgame. Most single volumes will do the job up to Expert level, e.g. by Nunn, Silman or Averbakh.
Hello I currently have my system and art of attack in chess. I was hoping to get another chess book. I've playing for about 3 years now so I would not say I am a beginner. I would say I am an aggressive type of player. Any suggestions would be great also explain how the book will help me. And if I would have to say anything I believe my biggest issue is openings. But in the middle game I just take over because of tactics and strategy.