Ok, scary thing you said "I am not versed in Linux" (usually I turn to Jello and not even answer posts when I see this). First, the cloud engines services might actually work for you, a little slow (according to some users, but they are probably talking about local access) but useable. I would try that first since that is what the Biz is all about. In fact that is it's main selling point - Cloud/remote access.

If nothing else works, here is another topic where webdav was discussed:
http://www.pogoplugged.com/forum/thread/15413/PlugApps-and-My-Pogoplug-integr...

But then, I would get help from some parishioner that knows Linux. Actually, the only problem with the Biz may be that it should have supplementary samba access for a more reliable local connection until cloud engines get their connector problems worked out, which is usually a faster connection. Ok, indexing may be another problem, but patience usually take care of that.

Actually for the arm/plugs depending on which way you go, plugapps, optware, debian, all the sites are mentioned in that one link so you should just explore. Let google be your friend. This has me a little stumped since I learned Unix probably 3 x Justin Bieber's age ago. Probably just google linux or unix tutorials. Anybody else care to chime in?