I just bought a used 2011 Mac a couple months ago, after using PC's exclusively for 20 years. It really only took me a couple weeks to figure out the differences. You have to force yourself to spend time at the computer even if it feels weird or frustrating.
The best thing I did was get the free ipad apps called SCOtutor for Mac and Mountain Lion. They are video tutorials that are fantastic...they break each segment into 1-5 minutes sessions, and they really help you get it down faster. The mac tutorial was free and the Mtn Lion was $4.99. Worth it, IMO. I would also recommend the magic trackpad over the mouse. Was way easier to manipulate the computer, using hand gestures.
Good luck...And btw, I love this mac and am kicking myself for not switching sooner!