Take a look at the cyclists forum.
It really depends what you want and what your budget is. For a basic, entry level hybrid bike which would be fine for a 2 mile commute you could get something reasonable for £200ish new. For an entry level road bike you're looking at £700 or so for something decent, but you don't need a proper road bike for a 2 mile trip.
Don't worry about hills, that's what gears are for. You'll probably feel like you're dying the first few times but it won't take long to adapt.