I have been GPU mining for a few hours on pool: 213.168.251.23:13654 (1%-5%-10%; UK;
How do I see my balance?
When I used the GUI cpu wallet, the balance on the same account still shows 0.0000
Balance should be shown in wallet. There can be some reasons, why you didn't recieve any payments.
1) you use very old version of miner that didn't work proper. Last released version is 0.1.0
2) the pool can be almost dead. Try to change pool
3) something is wrong with parameters. If pool has interface where you can see some stats for your address, check unpaid shares count for your address after some minutes you started mining.