You can definitely play around with different HA/DR configurations as Steve described. If there is something in use at your company that you aren't real familiar with or comfortable with, I'd probably set something that up as well. With those servers, you can totally hose things out and no one is affected.
You may want to emulate something like the storage totally going out, screw up the entire instance so that you can practice restoring everything - system as well as user databases. Being able to restore everything is incredibly important. Everyone can backup but it's not worth much if you can't restore.

Another thing outside of those servers is that you can also play around with some of Microsoft's cloud with a free account for a month. You can get some additional time if your company has enterprise or other agreements (spends a lot of money) with Microsoft. You'd want to check with whoever does your software agreements/licensing with Microsoft. Here is a link for the basic free account: