Which flash for my D90?

[kidloco]

Hi all,

I will be starting a photography course soon. Nothing fancy, just a night course. It seems I'm going to need a half decent flash. No idea what I should be looking at to be honest so any help would be appreciated.

So far I've narrowed it down to either;

A brand new Yongnuo YN-565 i-TTL (£100)
A second hand Nikon SB600 (around £150)

Don't really want to spend more unless I have to. Any comments on my selections or maybe there is one I've missed.

Thanks

 

[kidloco]

Cheers guys. I'll get the 565 and save myself £50. Plus ill get a warranty if its new.