Think he means just one skeleton, but meshes for sections of the body, so you make a totally nude body, and then cut it up based on the different types of clothes you'll use, so if you got a girl body and you want to put a pair of shorts on her, you can remove the hips and upper thighs, 'cos you have a separation in the mesh where the join is, if she was to be in a bikini though, you could leave the thigh section on, he's suggesting a way for you to save poly's in the final mesh basically.
I'd look at it differently, For instance by definition what you're trying to do is make it easier to come up with a range of models right? well, that means you want something quite simple to use, and since you say you're new at this then I guess you want it to run reasonably smoothly for you too.
The problem is that you want something modular, and designing a modular system is no small thing, but you've said you're determined, so I'll say, make a few models in the style you're thinking of, then try to find similarities between them, like 'lowest commor denominators'.
If you think two differrent things could pass for the same if textured differently, drop one and make that your archetypal whatever, say it's a pair of legs, one set's stocky and short, but the other's tall and sleek. You want a pair of pants that can fit both, and you'd rather not do two pairs, could you get away with scaling the same pair to fit both body types, if you design the mesh right?
That's the kind of thinking you could adopt to make a few models go a long way, and retexturing would complete the transformation.
Now you have an option to remove the hidden faces, those of the legs where the pants are covering them, like suggested above, and you design the body mesh so the feet, calves, thighs etc are removable, by removing groups of faces, so you could use some memblock manipulations to remove hidden faces based on whether they are showing or not, much like the hiding of objects offscreen, then by doing a simple weld, the mesh becomes whole again, including the pants rather than the legs..
It's not something I'd enjoy doing, and I've been modelling for a bloody long time now, but still, If you do do it it'll be a huge help to newbies and others who just don't know how to model, but most of your work will be in the learning to make comparative mesh structures work well together. You could achieve this more easily if you perhaps make your different body meshes have the same amount of poly's... Do you mean to make this as a character creation set for milkshape, or are you gonna code something in db to make it a standalone character maker?
ZX Spectrum 48k Issue 3, Radio shack Tape drive, Rank arena 12" T.V. set.