I would start with the sugar daddy forums here. Read the stickies. Everyone comes to their own conclusions about what a sugar daddy is or is not. That'll get you started. I loved that forum but ultimately quit checking it/posting in it because there were so many arguments over semantics. BUT there is also a LOT of fantastic information. Once I found a method that worked without fail (for me it's being genuine and honest, approaching them like they're a person and not something to fuck, not playing the game, and educating them about sugar arrangements--you'd be surprised how many sugar babies have been hurt by would be daddies), I moved past that forum.
Here are my key observations from my experience and from my education on sugar arrangements:
The legalities of it are a gray area.
Most get into it for the sex/money. You'll either move past this and have a real arrangement or you wont. If you don't, you'll probably sleep with more 20 year olds than you thought possible: but if you talk with them honestly, you'll find out that the cost to do that was to fuck with their psyche and confidence. You'll have to live with the fact that you conned a girl into become a hooker when she wanted an arrangement. Fight that temptation. Yes, you'll sleep with several girl while you're finding your baby: but be honest with them. Don't lead them on. Tell them you're still looking. Treat them well, and realize that they're giving you a fantastic gift. Don't be a dickhead just because you can.
Separate the hookers from the sugar babies. A lot of "sugar babies" are hookers trying to ride the sugar baby wave to regulars. If that's what you want, great. I don't consider that a sugar arrangement, but I'm not here to argue over semantics. Personally, I would advise to find the girls that are single, beautiful, sweet, and whatever else you want.
If you're not spending more time with her out of the bedroom than in the bedroom, I would ask if you really want to be a sugar daddy.
Emotions usually get involved, even if its more superficial than a girlfriend: they're still there... both ways. I've had several babies tell me they love me by date three.
My arrangements have been more like a relationship than any form of hooking; a few of them have turned into real relationships.
$3,000 per month is an expensive sugar baby. That's before you pay for dates and hotels! Damn! If you're traveling, that's even worse! I've had arrangements ranging from $800 to $1,200 per month, and all my sugar babies are beautiful, fit, 18-26 year old girls. I've had several races, from Asians, to whites, to Mexicans. I've never had a black sugar baby, but I've seen some other gentlemen here with gorgeous ones in the same budget range I'm discussing. The point: there is a girl for everyone in the ~$1000 price range. All in all, with dinners and hotels, you should be around $2,000 or less (inclusive) for an amazing baby.
If you still need to go cheaper, find a sugar baby that lives alone and make the deal contingent upon playing at her place. Now you're down in the $1000 range. This will really limit your options though. Only 1/10 will be comfortable doing this until they're very comfortable with you, and only 1/5 will have their own place. Most will still live with their parents, their boyfriend (very common to have a SB with a boyfriend; at least for me-- some daddies with autoreject a baby because of this; your call), friends, or be in college and in a dorm room.
You have the power in a sugar relationship. Most of the girls here hate it when the sugar daddies say that because providers have the power in hooking, and again a lot of the girls here equate hooking with sugar arrangements. In sugar arrangements, it's the other way around. There are a handful of would be babies for every "sugar daddy." And after talking with literally hundreds of potential sugar babies, I've found most "sugar daddies" are not legitimate. They're guys that either (i) don't have the money to fund their baby but dont tell their baby that until they can't pay them one month; or (2) are johns looking for a one time deal. As the result, the ratio is almost assuredly more skewed that that. I'm confident that there are dozens of would be sugar babies for every legitimate sugar daddy. My point: if you want to get her on BC and cum in her vagina, you can generally do that. If you want to try some freaky fetish, cool. If you're into rape fantasy great. If you want to have a legit threesome with two bona fide college girls,
. You. Have. The. Power. Most would be babies would have been through the ringer with a couple other guys, and are smart enough to realize that you were hard to find. She'll do a lot to keep you. But keep in mind, she is not a hooker. You have to approach it more like a GF. You don't just ask her how much to shove it in her ass. You talk to her about it (some daddies incentivize her with gifts: I've never had to do that). But it's different than a GF because you more than likely, she's going to ultimately say yes. If it's a healthy arrangement and you're holding up your end of the deal, she'll do pretty much whatever you want.
And SA is the standard website. If you want a non-internet based approach, see the SD forums here for suggestions. The business card method is really good.
Hope this helps.