How is this done?

I am trying to figure out what is the best way to produce some plastic pieces that I want made. I am looking into rotational molding right now, and I am wondering if anyone can tell me where I can find more information on this process. I am particularly interested in how it is done, and what types of parts it works best for. Can anyone recommend a good website for learning more about this process? I would also like to find out which companies are well known for using this process, so that I can find a good company to produce my parts.