If you've never carved much, or anything before, then a wood like birch will serve you well. Sycamore is also great for beginners at carving, and possibly Horse Chestnut.
Depending on what you want to carve, a short, straight bladed carving knife is pretty useful, as is a good hook knife, and a draw knife is as well. If you were thinking of something bigger, i.e. bowls etc; then an adze, either flat or curved is pretty much essential. You could also make good use of a Native American style crooked knife. For fine detail, you can get sets of small knives, similar to scalpels, all designed for this purpose.
http://www.axminster.co.uk/category.asp?cat_id=207918
There is also a tool called the polynesian crook knife, but I havn't got the faintest idea where to get one, and it is a pretty specialist tool, so you probably wouldn't need one.
Hope that helps,
Jake.