Poppyh, I've tried most brands and kinds of nappies over the years, so if you want to ask any questions about particular kinds, I'll probably have tried them .
You've got Flat nappies ( terries and prefolds ) with waterproof wraps. Cheap, quick drying, but more prone to leaks, and you have to fiddle about folding them.
There's shaped nappies with waterproof wraps. These are probably best all around - great containment, easier to put on. They come either in 2 sizes ( more expensive ) or Onesize, which can be adjusted to fit from birth to potty ( more economical. Take longer to dry than flat nappies though, but fine if you have a tumble dryer.
There are All in Ones, where you don't need a seperate waterproof wrap - these are the most expensive kind, take forever to dry and aren't great at containing leaks. Also in this category are pocket nappies, which are like all in ones but you place a seperate absorbant insert inside a pocket, which can then be taken out to make washing/drying easier.
Confusing, isn't it?! I think there is just too much choice, to be honest. The most popular kinds in this country - ie the ones which work best, are Totsbots and Motherease Onesize. I'm using a mixture of these this time around. Actually, I'm using a brand almost identical to Motherease called Onelife - exactly same style, just different brand.
I reckon you should read a few websites, ask a few questions and don't panic about vast choice, lol! You can get a lollipop or a babykind nappy agent to come to your house so you can see the nappies in the flesh before you buy - that's a great idea. Here's a few websites to get you browsing:
www.babykind.co.uk
www.kittykins.co.uk
www.thenappylady.co.uk
www.twinkleontheweb.co.uk
www.theclothresource.co.uk. . this one lists most online nappies shops.
Have fun!