Hi Walaa,
I started out with a pair of Celestron 15 x 70 and they're a great pair of binocs. They can get a bit weighty after several minutes of use. Learn some techniques with there use such as putting your arms close to your chest or as Paddy mentions use a deck chair and lie on that.
If your nifty check out the projects page and look for parallelogram mount - by far the best method in getting optimum use out of the binocs. Buying one isn't cheap and can cost as much as the binocs themselves.
You could also get away with small binocs such as 10x42, 10x50.
Andrews.com have quite a few to choose from and the quality is generally pretty good. In fact, my boy's got a pair of 8x42 and their as crisp as anything.
Welcome to forum and good luck.
Cheers Norm