Look on ebay too, get some good deals there too.
It all depends on how much you have to spend and what lens you want, its alright saying zoom, but how much zoom do you want, if you see what i mean.
You can get a canon 75-300 off ebay like I did for less than £100 but it aint the best lens in the world, but it will get you started.
Like said the nifty fifty is good also.
I also bought a canon 28-135 IS and i love this lens as a walkabout lens, it does a lot and was £190 off ebay.
Good luck with whatever you buy.
Spike