what image editing software did you use? you can do a lot more with it, it seems to me you rushed this. I like the choice of image though but as I've said, you can do a whole lot more with this
here's the deal... you need to resize the image to the width you need, and then CROP the height.... you can't stretch it out lengthwise and expect it to look good... the baseball players look like fatty boombalaties.... and the font style is dated.. try downloading some good fonts from dafont.com
Choose other color that matches both the text and the picture. Try to look other banner or tutorials, you might get great ideas from them.
Instead asking people to criticize you, why don't you check out a designing site. Or hire a designer. In fact you can do lot more in your site...
I think this banner would look better if it was the origial colors. A banner is supposed to catch peoples attention one color does not usually do that. Try some brighter text and not just the ones photoshop provides.