D90 would be well worth looking intoGet hold of a copy of "Understanding Exposure" by Bryan Peterson. You will find it a good read.
I dont know how much they are going out for, but the canon 450d 18-55 kit is selling for around £450 in some places ive seen on the net recently, its an absolutely fantastic camera, and im glad i spent the money on mine. Its very easy to use as well. My friend has a D40x, and I think the canon is easier to get on with.