Thanks to Michal's help, I have successfully installed Wikidot on a server at home. However, I'm still having problems hitting my Wikidot site from other PCs in my home network. I think it might be some kind of DNS issue. When I run Firefox on the Wikidot server, I can find Wikidot at www.dawiki (no ".com" per Michal's instructions - my server name is "dawiki"). The other PCs on my network can not find it through that URL. If I use the IP address of my server (192.168.0.108), I get the dreaded "The site does not exist." page.
Do I need to change something on the Ubuntu/Wikidot server or change settings on my Windows PCs or is it something else? Once I get this all working, I'll document all the fun I'm having for the rest of you! ;)