I suggest you post them up here before submitting them, that way you can get some c&c. Make sure the photos are suitable to sell as stock, also make sure the quality is decent at 100%.
The photos only need to be 2.5MP I believe so if you are using a camera that is 6-8MP or something, I would edit how you want, and then resize it some to make the quality appear better.
They are very picky on noise, so make sure the images are pretty clean.
The first 10 images from this link are the ones I submitted as my first 10, all were approved. Good luck! :byye
http://www.shutterstock.com/gallery...ws_per_page=4&thumb_size=large&safesearch=off