Your new iMac is running Lion v10.7. When you can, to see that information click the Apple menu icon top left corner of the screen. From the drop down menu click About This Mac.
You can sign up for One on One if you are near an Apple Store > Apple Retail Store - One to One
And there are online video and text tutorials > Apple - Find Out How - Mac Basics
For Windows switchers > Apple - Support - Switch 101