Get thee to a good critique group.
Critique groups can be wonderful, informative gatherings, or they can be the spawns of the devil. What they are suppossed to be is a group of like-minded writers helping one another bring their manuscripts to fruition. They are really the first thing that should see a manuscript. It shouldn't be an editor or agent. It needs to be your writing buddies.
The problem, though, is finding a good critique group. It almost always takes a few tries before a good group -- where everyone feels comfortable -- emerges. And then you have to keep that group going. But when successful, critique groups are the greatest writing tools you can find.
Where can you find people to start a critique group? Well, I recommend the SCBWI as a good starting place. There are also some online groups and communities. You could always try there. Feel free to add suggestions of other good ways to find people for a critique group.