I have a Nikon D60 and got one for the wife as well and she has been bitten by the photog bug!

I am looking for a fast lens and want some advice please
I dont think it needs to be a long zoom (and I cant afford that anyway!)

I really am not sure what focal length to go with
I havent got any prime lenses and I am not sure what to go with if I decide prime is a way to go
I would like it to have Auto Focus - so for the D60 I think that means it has to be an AF-S lens

Some I have been looking at are:
Nikon 35mm f1.8, the 50mm f1.4 and the Sigma 50mm f1.4, or 24-70mm f2.8

Is there anything else I should be looking at or considering?
Price range is under $1000