Here are some tips where to find helpful information:
The recorded class A Crash Course in AutoCAD for Mac from Autodesk University 2011 provides an excellent introduction to AutoCAD for Mac and what the main differences to the Windows version are. (You may need to register on the AU website to see the recording).
You can find a detailed feature comparison chart in the Knowledgebase Article
How is AutoCAD for Mac different from AutoCAD.
If you want check if there are any differences in specific areas or commands, you can look up the command or variable in the AutoCAD for Mac Online Help.
Another great resource is the AutoCAD for Mac Wiki Help which has many great tips from the user community in addition to the normal help content.
The AutoCAD for Mac Discussion Group is another great place to look for information, and to ask any questions you may still have.
If you would like some more in-depth technical information on differences in areas like customization and CUI, and configuration tips for a mixed environment, the materials from the Autodesk University 2011 class Working with AutoCAD® in a Mixed Mac® and PC Environment have lots of great advice. (Unfortunately the class was not recorded, but the handout and presentation slides are very comprehensive)
And - last but not least - the best way to find out things is often to just go ahead and try it out for yourself :-)
You can downlod a fully functional 30 day trial version of AutoCAD for Mac here: