SMF - Just Installed!
That's nice and I think you could learn a lot just by studying that. His models are pretty amazing!
Would like to see this textured and rendered.
That's a good start vellum. Even with just some texturing and perhaps bump mapped detail (or whatever the latest technique is called these days) that could look passable. Like you said, at least you're learning it. Were the stairs going down into it hard to do? looking forward to seeing your progress on this...and I have to rep you for wading in there! 
If you ever need help, Robes has used it a fair bit as you know. Did I just pass the buck there? lol I can get you some pics from role playing sources if you want...I'll try. Every little helps right? Well, let me know, maybe you've already made up your mind on sources.
Can't wait to see how development of Outerra's biomes goes...and would love to see a few models springing up too. That's probably the number one thing that will cause ip issues. All I say is if you're going to use use them, tweak them enough to make them only suggestive.