How to get Mac OS X to run in a VM on Windows
You can technically run Lion in a VM, but I really really really wouldn't recommend it. Here's why:


You're basically entering the murky world of Hackintoshes
Hackintoshes are inherently "hacky". The performance is rarely going to be as reliable as running OSX on mac hardware.
You're violating Apple's EULA.


If you really want to do it, here's a link, but I really think it's a fool's game.

Recommendation

You'd be better off just getting a Mac Mini or something and if you really want to run Windows natively, then remote desktop from Windows to your Mac mini. I'd recommend that.