Complete beginner?
Join a club
Take a course
Rent studio space
What sort of model work are you wanting to shoot?
Fashion, glamour, beauty?
Do you want to be able to create sets or just shoot on a constant white seamless backdrop?
Are you looking at building a permanent studio or a temporary one?
Full length shots (fashion & glamour) will need a lot of space.
For white seamless read this (all 5 parts)
http://www.zarias.com/?p=71
For understanding flash and setting you on the right direction, the OneLight DVD's are worth investing in.
For shooting glamour, have a look at Jason Cole's DVD (he's usually found in the Glamour section of the forum)
I started with one hotshoe flash off camera, added more, bought a backdrop etc.
Now I rent a studio when I need it, it's easier and someone else has the worry of buying and looking after the gear, insuring it etc. I just turn up, setup and shoot.