well if I remember correctly there is an article in the article section (duh !!) about doing conversions. As for a specifique site can\'t think of any, but just browsing the sites you should find a couple with conversion articles.
You can find lots of information here. This section contains plenty of discussions regarding various conversions and then you can read Cyril\'s article on basic conversions. Hope it helps!
*edit* and of course someone beat me to it while I was typing my post
I should have known Finn was going to be faster than me
You don\'t need a web site.
Just get a guy with arms already separated or held away from the body and change the position. That\'s good for a first. Once you do that you understand much and will be enthused to try more.
Setting yourself a high goal could be discouraging because it\'s a whole new set of skills.