virtualbox.org

Hello!
I've been happily using a Fedora 18 guest on a Windows 7 host.
I'd like to get a NAS for my lab to centralize data storage for several computers.
I was wondering what options exist to integrate a NAS into a guest VM.
Many modern ones seem to have web interfaces, so I assume that will work fine.

Does anyone have any NAS/VM experience and/or suggestions?

The fact you are using a VM makes no difference to an external entity, like a NAS on your network. Just think of your VM as another regular machine for this purpose.