I'm a relative newbie to DSLRs and have a d5000 which I got last year. I've stayed with the 18-55mm kit lens so far as I couldn't afford a larger zoom. Now I can, I am unsure whether to go for the 55-200mm which is around 150 or the more expensive 55-300mm at 230.

I can afford the bigger lens but would I be better off with the 55-200mm and then maybe getting a bigger lense say 70-300mm (or more) later on?

We go to Chester Zoo a lot and so it is wildlife shots that I am most interested in taking with the zoom lens.

Thanks for any help on this