Hey,
Regarding the sites, start with the big names (pornhub, xvideos, etc.) try them all out, you will see which site works the best for You. That's how I did it. Some of them are great for 1 niche (I work with 3-4 different niches) and some are not so much. You'll see.
...and 1 day you will just tap into a great niche, then do not let it go. I just did find one, I opened the account (with private proxy) and registered a name, filled in profile info (very important), uploaded a profile picture. 30 minutes later I had 30 friend requests, LOL.
Then 200 and so on and that time not even 1 single video was uploaded. Then you can also try to convert those friend requests, most of them will write you, ask you out, give you their skype username, etc. ...you will see.
Don't bother with imacros, better to buy a private bot (works best for me) for uploading or you can also try adult AVS.
Those guys are really good.
Hope it helps a bit and you will start making money. There will be days when you make a lot (I had days with $70-100 / day, then it drops to $10 or so...there is no pattern anymore about people's spending behaviors.)
Oh, one more thing. Try to mix your offers, go for revshare, pps, ppl too.
Good luck!
L.