i would either buy a canon or a nikon, not because they are better than other makes, but because its easyer to get lens for!

do you want new or secondhand? as alot of people upgrade for the newest flashy machines even when they dont need too!
you can have a nikon d60 (which has only just gone out of production) with a 18-55mm vr lens for about 270 quid!

or if you want new a nikon d3000 is just under 400 quid including a 18-55mm lens!
dont worry about buying other lens straight away, just et used to the controls you have!
theres some AMAZING lessons in the photo area on there and will defo set you on the right track!