I agree with Happyz. the Standard Videos on HUSNG.com are nuts, and after studying them I was able to beat the 5s, 6s, 11s and 15s over 4000 game sample size.
My opinion on tagpoker.co.uk:
I respect what they have done. And they are teaching a pretty unique strategy for beating fish. So go for it if you want. But be prepared that you have to adjust your game a lot when playing against good players.
That's the reason i think husng.com is better, because it is a bit more of a standard strategy - especially in the standard Videos.
Of course what Polycarpus said is also a good idea, maybe you find someone to review your HH. You can send me a PM if you want, I love to review Hand Historys
At small stakes it is often just a few basic leaks you have to find in your game to be much better than the average player. You should find your leaks either way, by watching Videos, reviewing HH and talking strategy here in the forum