Go too: http://www.gbrcaa.org this is the GB aerobatic site have a look on the left and you will see a block in light blue with a "New to Arobatics" click and follow from there, should give you some guide lines.

I know that my main failing was not flying straight and level, always had one wing down, even though I was convinced I did not and it took a pal with a video to convince me, also flying a straight line in front of yourself, easy isn't it, get someone to stand approx 100M in front of you with a flag and let them indicate too you when you are not on line and crossing overhead at a constand distance from you, the poor chaps arm got so tiered he had to stop, then it was time for revenge. Seroiusly if you can get someone who also wants to start it can help greatly as you can share the load, and get your own back on each other.

Mike