Yellow-Rumped Warbler

This image was taken on a cloudy day in Harrisonburg, VA. It was shot at 1/640, F/4, at ISO 640, on the 7d with the 300mm F/4. This was only my third time out with a DSLR, so I am still trying to figure a lot of things out. Other than adjusting a few levels, and a heavy crop so that the file size would be correct, I have not done anything to it in post-processing. Any advice/critique is welcomed. Thanks!

Hello Will, welcome to the forum. A few things that would have helped you would have been a higher f/stop, ISO and shutter speed.
I'm sure the 7D would have handled that, also I hope you are shooting in raw. The image needs to be sharpened and the small twig that runs through the tail removed, but we can worry about that later.
Next time you could raise the bird in the frame and to the right a bit would help the composition. These things take time but I'm sure you will get the hang of it in no time.

-Tim