If you want to go with prefolds and covers I highly recommend greenmountaindiapers.com They are the gold standard of prefolds. We have been using the same prefolds for 18 months and they are in fantastic shape. If you want to go with a one-size pocket or one size all in one diaper take a look at pinstripesandpolkadots.com
The great thing about pocket diapers is that you can adjust the absorbency and they dry faster than aio's. Prefolds are the least expensive way to go but are a little less convenient that pocket diapers. I prefer a one-size so you get more bang for your buck. Thristies Duo diaper will go from 6-18 lbs and from 18-40lbs!
Just to touch on Carrie S.'s concerns-you don't have to change that frequently. Typically it's about every 2 hours. If you have those kinds of issues it's usually the type of detergent you are using, using too much detergent, using other agents that you don't need like bleach, vinegar, baking soda or the diaper isn't getting rinsed well enough. Diapers need an initial cold rinse cycle, then a hot wash (with a tiny, tiny amount of detergent-like a tablespoon)/rinse, then another hot wash/rinse cycle with nothing just plain water. Water is your friend with cloth-gets them clean and non-smelly! Also, it's important to use covers designed for cloth diapers that are made with a breathable waterproof material. And you won't find those in wal-mart or babiesrus. :)
I tried gdiapers thinking they might be a good alternative when we were out and about. I didn't like them at all! They were far messier than cloth when baby pooped.