Bike noob needs help with purchase
 

Ok, here's the deal. I have no idea what I am looking for and all my friends THINK they do, but they don't, so I thought I'd turn to the well educated, ie. this forum, to help me out.

I have a budget of £200 and I'm looking for a bike. It will be mostly used to for getting around Sheffield city centre, and for those who don't know (the vast majority I presume), Sheffield is very hilly and up and down. But Sheffield is also quite close to a nature district with lots of fun bike trails, which I will go on, say once a month.

So I am looking for a bike that will be mostly used for getting round an up and down urban area, but from time to time will be used for bike trails within the region of £200, what the hell am I looking for?

Thank you.