Kramnik once said he's not sure he'd win QvR against tablebase. Should give you some impression on how tough it can be.
Dvoretsky's book had a small chapter on QvR, you might wanna look there if you're interested. But it's likely you'll forget everything by the next time you'll encounter this endgame, it's pretty rare.
I sometimes practice endgame tactics on chesstempo, and I got into a situation where it was K&Q v K&R. That was obviously a fail, I was supposed to get the rook before I promoted the pawn. Nevertheless, I decided to try to win with K & Q. I couldn't figure it out.
So then I turned to two endgame books I have, and I didn't see any chapters headings on Q v R.
Is it impossible to force a mate with K&Q v K&R? If it is possible, can someone point me to some written material on it?
Thanks!