All cam sites require a scan of your legal ID and then a picture of you holding that ID next to your face, it's so that they can verify your age, and is completely legitimate. Don't wear your disguise for verification pictures - Since those pictures will also include your legal ID held next to your face, the camsite will NOT make them public. Your appearance needs to match how you look on your ID, so if you're planning on wearing wigs/contacts/etc., forego them for verification pictures, then wear them for any pictures you put on your camming profile and of course on-cam.
Also, please be aware that no matter how well you disguise yourself, no costume is infallible, and if you start camming, there WILL be pictures/videos of you uploaded to capping sites, forums, tube sites, etc. If you're not comfortable putting your 'real' face out there in the first place and think that a disguise will somehow save you from being discovered... you might want to re-think becoming a camgirl. So many girls don't think this through and then freak out when they realize their pussy has been spread across the internet FOREVER. Be sure you know all of the risks (and rewards!) before diving in.
I don't disguise myself in the slightest, but these are all important things to remember and keep in mind when deciding whether to jump into camming. :twocents-02cents: