Can any one tell how can i trade via Forex trading in UK ? Because i read about it many times during surfing the web.

Answer
You can simply download software, install them on your computer and you can start trading with Forex.
You can open an account at Plus500 (which is UK trading machine authorized and regulated by the Financial Services Authority) and get 25EUR Forex bonus with no deposit to test their trading platform without any risk.

What is a good website to learn the basics of Forex trading?

I just attended a seminar on Forex trading the other day. I've downloaded a demo version of AVA FX and Im battling to get the most out of it. Is there a more simpler version out there from another company that will also run on my Mac because AVA FX only runs on windows.

Answer
Try with this Forex trading simulator
http://www.bullbearings.co.uk/fx.trading.guide.php
It's online and you can register for free, they give you a credit of £100,000 to place your trades. This site also has tutorials and advice. I started using it for stock trading but now I am hooked up with forex