Parallels Win 7 works great you just need to make sure you install itunes first, then plug in your phone so it can connect to the VM but dont let it sync. If you get pop up boxes asking to continue to use usb just click yes.
Make sure you follow the screens on Limera1n regarding power buttons, when it says let go of power do so, but dont let go of home until it says its complete.
You need to 4.1 first. Also if you want to keep the 1.59 baseband use Tinyumbrella to save your ssh. The upgrade through itunes on Mac, once it upgrades you will get an error from itunes and iphone will be stuck in DFU this is because of the baseband. Then go to Tinyumbrella and kick it out of DFU.
Then Limera1n in windows and have fun. Cydia has been having issues but only because high traffic.
Questions just PM me