Your map is very good for a first one, I like the textures that you used. The only thing that I really have to comment on is the rivers. Several rivers are going form ocean to ocean, that is not supposed to happen. Rivers start when mountain snow melts or from excessive rainfall, then they will flow into a sea or ocean using the shortest and steepest route. (In a few cases, a river will flow into the ground or dry up completely before reaching another body of water.) Several rivers will merge together as one, but one river will never split up into several (unless it is man-made).
For more about rivers, you should see Redrobes' post on how to get your rivers in the right place.