lol, as you can see this is not a scam WavesSea, so you're ok
and Dan has posted in here to show you it isn't.
He basically just wanted to let you know that he has a room for rent and that he most likely contacted a few people (including yourself) that posted on the macoffcampus site to see if there was interest. As for the link, Mac students are allowed to host small websites via their muss account (by adding the ~username to the end of the url) so he was just utilizing that service.
By the way, really nice looking house Dan! A huge backyard with a porch and BBQ... thats sweet. Wish I had that
Whats the monthly rent rate? You don't mention a rate in the ad.