So my friend offered me a deal on a dc5000, does anyone know about these cameras? Is it good starter camera?

You mean a Nikon D5000. Not knowing what the exact deal is, nor what lenses & accessories are involved, it is impossible to say whether it's a good deal.

Almost any Canon or Nikon dSLR within the last 5 years should be a good starter camera for urbex.

(The big two, for reasons of their extensive and ubiquitous lens and accessory availability. The big two, also for the huge user base that exists that you will need to draw upon for the knowledge base, since you are merely starting.)

I will say that a Nikon D5100 is better. That one has a 16.3mpx Sony sensor that was a benchmark for a long time (obviously now superceded) and ended up in a lot of cameras, including a higher-end Nikon (D7000), many Sonys, and still in production for a few Pentaxes.

I sold a like-new D5100 + 2 kit lenses + bag for $500 about a year ago.

Probably more important than the camera is what lens it comes with too!

I have the D5000 (it is my first DSLR). How much is he selling it for? It may be a good camera, but not as good of a deal as you might think. Especially if you're unfamiliar with cameras.