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I have got an iMac with OS X Mavericks and a PC with Windows 8.1 Pro. I do not share anything between those ones, but you can start homework in one of them and finish in the other one without any issue. Just make sure you choose the right application to do it.
For example, if you use Microsoft Office on the PC, the best thing you can do is to install Microsoft Office for Mac on the new iMac, so you can use your PC documents in both computers and modify them without any issue.
Both of them can be connected to the same printer. This will be even more simple if you have got a wireless printer, so you do not have to use any cable or do difficult things to make the printer work on the Mac.
OS X is completely different than Windows respecting to the user interface, so it is a big purchase. However, the interface is easy to learn and you will not have any problem after a few hours. Also, Apple has got some articles and videos about how to start using a Mac > http://www.apple.com/support/macbasics/
You may find this useful:
Switching from Windows to Mac:
and possible even the 'propaganda bits':
Macs are cheaper to own that PCs: http://techpatio.com/2010/apple/mac/it-admins-total-cost-ownership-mac-less-pc
Why will you love Mac? http://www.apple.com/why-mac/
- Better Hardware http://www.apple.com/why-mac/better-hardware/
- Better software http://www.apple.com/why-mac/better-software/
- Better OS http://www.apple.com/why-mac/better-os/
- Better Support http://www.apple.com/why-mac/better-support/
- It's Compatible http://www.apple.com/why-mac/its-compatible/