Send me a friend request and I can help you understand the. I do know quite a bit about how the model system works inside Q3. There is (was?) a freeware alternative called Gmax that Autodesk released but I haven't used it and I'm not sure how well the plugins work. Unfortunately I cannot provide links to 3D Studio Max as it is commercial software and I'm not sure where to get a copy of the outdated versions at this point. The main reason for this is the exporter that Pop'N'Fresh wrote as well as the importer that Chris Cookson wrote work for those versions and you will want those if you are wanting to get into this. I know in the tutorial on the page BadMojo linked to Steed refers to Max version 2, but I recommend release 4.2 minimum and release 6 at maximum, as well as Character Studio (this is built into Max 6 I believe and is separate for Max 4.2), as well as some import/export plugins. You will need a few pieces of software to make a custom model - an older copy of 3D Studio Max.
There used to be a good tutorial for biped rigging on loonygames but the site is gone. There's also some books out there on Amazon and some other places. Anything written by Paul Steed is going to be helpful as he did the player models in Q3.
