Looking to purchase

I would recommend a 13" or 15" MacBook Pro with minimum 4G of RAM. 8GB would be better for the little extra money. As far as apps, most everything you need comes with it, but in your line of business, you might want to consider Microsoft Office 2011 or Apple's iWorks also.

If you want to save a little money (15 to 20%) check out the refurbished MacBooks and MacBook Pros in the refurbished section of the Apple Store http://store.apple.com/us/browse/home/specialdeals/mac?mco=MTM3NTA4MTI

These have the same warranty as any other Mac and you can buy AppleCare for them.

If you want to save a lot of money you can try eBay. But you'll need a friend who really knows Macs to help guide you.

MacBooks: http://computers.shop.ebay.com/Apple-Laptops-Notebooks-/111422/i.html?Product%25 20Family=MacBook&Processor%2520Speed%2520%2528per%2520Core%2529=2%252E0%2520GHz% 2520or%2520more&Processor%2520Type=Core%25202%2520Duo%7CCore%2520Duo&Memory%2520 %2528RAM%2529=512%2520MB%2520or%2520more&Hard%2520Drive%2520Capacity=60%2520GB%2 520or%2520more&LH_ItemCondition=3000&_nkw=13.3+apple+macbook&_trkparms=65%253A15 %257C66%253A2%257C39%253A1&rt=nc&_catref=1&_dmpt=Apple_Laptops&_npmv=3&_sc=1&_st icky=1&_trksid=p3286.c0.m14&_sop=1&_sc=1

MacBook Pros:http://computers.shop.ebay.com/Apple-Laptops-Notebooks-/111422/i.html?LH_Auction =1&Product%2520Family=MacBook%2520Pro&LH_ItemCondition=3000&rt=nc&_dmpt=Apple_La ptops&_sc=1&_sop=1&_trksid=p3286.c0.m282

And to save more money don't get Microsoft Office or iWorks unless you can get them installed free by your school. Instead try the free program Open Office For Mac. http://porting.openoffice.org/mac/ It has all the features of the other programs and can work with documents created by them.

For playing DVDs, playing music and using the internet Macs come with DVD Player, iTunes and Safari installed as part of the operating system. And Preview is a mini-PhotoShop for working with pictures. Preview can also read .pdf files.

Currently macs don't get viruses. But there is malware and trojans that you can get. MacProtector is the biggest one right now but it is relatively easy to get off of your computer.

A newer free version of Office is LibreOffice. http://en.wikipedia.org/wiki/LibreOffice

You can download it here http://download.cnet.com/LibreOffice/3000-18483_4-75337652.html

Not sure where you are in the world, but many areas have discounts for students and education professionals, both on hardware and on software. Certainly worth checking it out with your nearest Apple store or authorised retailer.

I've never tried LibreOffice but if you are teaching, you should probably just get Microsoft Word. It has some great features especially the publishing view.

A macbook is more than sufficient.