OK..I'm new to this designing thing so can someone please explain the whole brushes concept to me..&& could you also show me where I could get some pretty nice ones.:)

Brushes are like stamps you apply to an image. As for where to find them, there are a good many out there. All you have to do is google.

Try my site: http://www.paperxairplane.net
I've got some brushes :)