Deffinently download Mike's tutorials likez1mmnd14 says. Along side of that, you should also be aware of what happens to your renders when you're batch rendering. Here's how it works. When you batch render, Maya is rendering one frame at a time and storing the images in a folder somewhere on your computer. If you have batch rendered several times, but haven't been able to access your render afterwards, it's because you don't know where they are. By default (I think) Maya directs the files to My Documents>maya>projects>default>images or some folder inside the default section. Anyhow, what you need to do is set up another place to send your rendered images during batch render. I created a folder on my desktop for them, but you may want to do differently. Once you have choosen a file to send the images to, you need to tell Maya to do that. Choose File>Project>Set... A browse window will come up. Select the file and click OK. Now all your rendered images during Batch Render will go there.
As said before, watch Mike's tutorial for info on the best settings for Render Globals. If you don't know already, Render Globals greatly effects you batch renders in size, quality, everything basically.