Another Recommend me a DSLR

So the Girlfriend wants to get into the DSLR world. Recommend me a good DSLR for starters. She did take a manual photo class in high school so i know she is familiar with manual adjustments and i know she enjoys it. Her birthday is coming up and i want to grab her a nice toy to play with in the fall!

That being said i really want to stay in the Nikon family for the most part but there is a nice SONY at bestbuy that i was playing with yesterday! and seemed really nice. i know SONY UI’s usually suck for the most part… so any input would be great!

D40 (6.1 mp): http://www.bestbuy.com/site/Nikon+-+6.1MP+Digital+SLR+Camera+-+Black/8139169.p?id=1158323379076&skuId=8139169
D3000 (10.2 mp): http://www.bestbuy.com/site/Nikon+-+10.2-Megapixel+Digital+SLR+Camera+-+Black/9456803.p?id=1218107268800&skuId=9456803
D5000 (12.3 mp): http://www.bestbuy.com/site/Nikon+-+12.3-Megapixel+Digital+SLR+Camera+-+Black/9311755.p?id=1218082646627&skuId=9311755

I know there is alot more to the cameras than the megapixels but… thats pretty much all i know… so… help me out here. we would like something for beginners - novice because i know she will pick up on this stuff very quickly and i dont want her to grow out of the camera for a while.

I cant find a link to the SONY i was playing with… Oh and I would like to keep my budget around $500.
edit: http://www.sonystyle.com/webapp/wcs/stores/servlet/CategoryDisplay?catalogId=10551&storeId=10151&langId=-1&categoryId=8198552921644718498&N=4294952674&Name=%26alpha;+NEX+Digital+Cameras#/nex5Section&XID=O:digital%20SLR%20cameras%20on%20sale:corp_alphaso10_gglsrch:mt_ph

this camera felt pretty solid and it was tiny compared to the rest of them!

Is there anything i should know about buying used? i imagine that buying a used camera should be a good route because they cant see too much action/damage

---------- Post added at 09:15 AM ---------- Previous post was at 08:52 AM ----------

Also what is a D60 worth used obviously