I think a good quality flash unit is a must. My photos took a leap forward when I got mine, it takes a while to get used to it but the results can be worth it. Now I have a set up to get it off the camera it's even better. It is not money wasted, they seem expensive but it is worth it.

I would defiantly get at least one other lens. I like Mark's suggestion about looking at what focal lengths you are using etc... but I bought a very cheap 50mm f1.8 lens and it really opened up what was possible with the camera. I am sure Nikon do a similar model for £50ish. There is no point in having a DSLR unless you have some very good lenses for it. I would go as far as saying the body itself should be the cheapest part of the set up. I have a f2.8 24-70mm for my 40D and it was worth every penny. But the 50mm prime is a good way to start and as a prime lens will force you into framing things properly. It's a good start on the right road. I took this shot the other week on a 180mm prime lens...



A recent purchase for me is a monopod. I have had a really good tri pod for a while, but I find a mono pod really really useful. A small and light weight one that can hook onto your camera bag would be very useful. Of course I went and got a great whopping Manfrotto 685B but it is pretty fantastic. Shots like this need to be pin sharp and without the monopod my hand just isn't steady enough...



Anyway, you have already made the most difficult decision in digital photography. The old Spectrum or Commodore argument of Canon and Nikon. You have chosen to be a knuckle dragging Nikon user ( ) I would say that as I use Canon. The very next thing I would do is to set yourself some photography assignments gets some books, download some online tutorials and learn how to use it before you go on holiday.

Cheers

Cris