HERE ARE SOME TIPS !!!
First of all GOOGLE IS YOUR FRIEND !! GOOGLE everything someone sends to you and type the word 'scam' by it and see what pops up before even take anything serious. if you find nothing then ask a million questions.
before you accept any job make sure u know the job/gig at hand, and if you are comfortable with it. Then ask questions about compensation. if these ppl are going to expliot you, which is what modeling pretty much is. Make sure you are getting paid for it, of that itll look good enough for your resume, or if you can use it as a teer sheet (any photo in a publication, magazine, relaxer box, etc) model mayhem sites are good but its alot of ppl like everything else these days who pose as "PHOTOGRAPHERS" just get girls, talk to girls or even worst.
Anybody with a camera does not make them a photographer. Ask to see portfolios. Make sure you speak with models who have worked with tis person or company before.
Its best to have an agency because they play the middle man for you, and take care of all the legal issues and make sure ur getting paid. But beware of fake agencies. or agencies that ask for money to represent you. If they truly believe in you theyll sign you because the know theyll make comission (maybe 10 %) off of you with everyjob you get. so real agencies wont ask for money.
They may be times where you have to spend money if you want to work with professional photographers you like. some scam with agencies is that theyll send u to a photograoher they know and will split the money with them, and after your photoshoot ull never hear from the again. they will go as far as to send yu to fake audtions they set up so that u believe they are a real agency.
As much as i can go on, the MOST important thing about modeling. is to be modeling something. Ass shots do no count. of course i had to learn the hard way because i thought as a black model with shape this is what i had to do to be successful. but it does nothing for your portfolio and your stuck with photos u grow to hate on the internet. lol.
hope this was enough. GOOD LUCK !!