That book should be good enough for you right now for openings. Read his other books, winning chess tactics, winning chess endgames, etc... I think there is 5 or 6 altogether.
Thats should help you get to 1400 about.
Don't waste your time studying openings. Spend that time on tactics. Usually at the lower level, games are won/lost because of tactics.
1.Open the game with e4/d4
2.Move the knight to f3, c3
3.Move you bishop
That's basically all you have to worry about right now. Always ask yourself, why did my opponent make that move. Check for tactics, hanging pieces, pins, skewers, etc...