Problem after Problem... Now the wheel bearings

Rear wheel bearings have gone in my A3 Sportback 170TDI s-line FWD .. well i think anyway, i thought it was my tyres because they were on the limit and worn on the inside so i had those changed and the whining is still there. I can only put it down to wheel bearings now as it starts whining from about 30mph and get louder and more annoying the faster i go! Im sure problems follow accordingly Anyway.. any ideas if you dont think it would be the bearing and also good places to get them from and are they easy to fit.

Cheers
Grant