How do I get into acting?

I really want to be an actress for a theatre production, commercial or a film but how do I get into that sort of stuff?
I have done one little documentary on the New Forest national park and I really enjoyed it.
I live in the UK though just so you know.
And how do I get an agent?

First thing you want to do is make some well-cropped, 3/4 view body shots of yourself. They should be either color or black and white 8″X10″s. Some smiling, some serious, some with a quizzical look. Have fun.

Next, get an agent. The agent will pound the pavement and get back to you with auditions he/she wants you to go on.

http://acting411.blogspot.com/2007/09/how-to-get-agent.html

Finally, go on the auditions and knock ‘em dead! You can do it!