a lot of those websites are scams, while there are several social networking websites for models, photographers, stylists, and muas, there are absolutely no websites for model scouting.
all legitimate agencies who specialize in model management insist that all models come in during an open call. most agencies have a day setup each week, like a tuesday, between the hours of 2pm and 4pm for new models to come in to be looked over. normally you're expected to bring a few polaroids of yourself and possibly a portfolio. if they like you, they'll send you to a photographer they want you to test with. the photos taken by the photographer normally cost around 300-1500 dollars depending on how involved you want the photoshoot to be.
(photographer's fee ranges from 300-1000)
(mua 300-500)
(wardrobe stylist 300-500)
(hair stylist 300-500)
of course, these fees can change, especially if the mua or stylists are just starting out in the industry or feel like doing charity.
**Also, most agencies are looking for models that can double as runway models, so basically 5'8" to 5'10.5". anywhere in that range, a size 4 dress size, and hips that are <35 are the norm.
If you are outside of that range, most large agencies won't sign you or ask you to come back. if that is the case, then print modeling is probably the only other pursuable option. in that case, it becomes much more difficult to find work.