Some model questions

I've been working on this nice (for a noob) model for some time, and I have a few questions about it (I am using milkshape, btw):

1.Does it matter where the model is positioned? That is, should it be above the center of the grid? (if you don't understand this, i'll post a picture later)
2.I noticed something in a Blizzard .mdl i converted from a mdx- it said somthing about a "bounding box" and "bounding circle". What are those exactly?
3.I have found that MDL files are incredably hard for me to understand. Any good tutorials anywhere?
4.I think I kinda get what unwraping is (tell me if I'm wrong, but its taking apart the model so you can skin the different parts of it). How would you do this? Do I need another program besides milkshape?

I'm guessing this is all in a tutorial somewhere, but I couldn't find one about milkshape. So, anyway, thank you for your time and for putting up with my newbie questions.

Oh yeah, here is my model:

hi

1. yes it does matter
the feet must be over the ground and the model must be in the center in top view
the front of the unit must be in front view

2. don't know but its not important for editing (just leave it like it is)

3. there are some in this forum but I don't know where

the only important parts you'll need are sequence, texture, material and the materialid at the end of every geoset

all other parts are for FX it is better not to change them at the beginning

4. unwarping is like placeing the polygones on the texture
you can do it with milkshape 3ds-max or gmax (so far as I know)

I hope that helps for the moment

C U Ced

Yeah, that helps a bit. Thanks.