Here tips from Grandmaster Susan Polgar:
1.Control the Center!
2.Develop your pieces as soon as possible!
3.Castle as soon as possible!
4.Do not bring out your Queen early!
5.Do not move the same piece twice, before you have completed development! (unless it is being attacked or you can capture something for free).
Chess Strategy - Tips from GM Arthur Bisguier
It's time for you to take a look at these ten tips to help you learn some simple ways to win more games:
1. Look at your opponent's move when you play chess.
2. Make the best possible move when you play chess.
3. Have a plan when you play chess when you play chess.
4. Know what the pieces are worth when you play chess.
5. Develop quickly and well when you play chess.
6. Control the center when you play chess.
7. Keep your King safe when you play chess.
8. Know when to trade pieces when you play chess.
9. Think about the endgame when you play chess.
10. Always be alert when you play chess.
Don't rush when you play chess. Take your time and be sure to study the examples carefully. Then go out and practice - and have some fun!
Hopely it helps you.. Have fun.
Read Silman's Reassess Your Chess. It will definately get you over your hump. Take your time reading it. It gives you plans on what to do in the middle game. It teaches you what to watch for, loose pieces, holes, solid squares to get you N and/or B to. . . much more. I'll sell you my copy for $8 shipped. PM me.