If you are a Mac user, you will be able to go through your courses without any major problems however we do recommend a few things to make your life (and your instructor's life) easier:
We recommend you use the Firefox or Chrome web browser, instead of Apple's Safari web browser due to some known issues. You can download the latest version of FireFox here. You can download the latest version of Chromehere.
We recommend that your Apple computer has the Mac OS X operating system installed. Preferably OSX 10.5 or higher to limit any major issues you might encounter. You can find this information by clicking on the Apple on the top left of the screen, and selecting "About This Mac".
Always make sure that your Mac is up to date with the latest updates. To check if your Mac operating system is up-to-date go to Apple's MAC Updates web site.
Please use the Microsoft Office application for Mac if at all possible. Please see this article for Microsoft Office for Mac best practices. (Specifically see the note on using file extensions)
If you choose to use the Apple productivity suite of products instead (Pages, Numbers and Keynote) then please make sure you save the files in the Microsoft Office format (Ie. Doc/Docx, Xls/Xlsx, and Ppt/Pptx). Please note that formatting might be slightly different when saving in this format. If formatting is graded, review your document after you save it in the MS Office format.