Perhaps the best advice at this stage is: "If you want to take pictures, hire a model. If you want to fuck, hire a whore."
So treating your model with respect is the most important ingredient to a good working relationship and the key to capturing the sort of images that will sell. If you can't get past this, you should find something else to do.
Cover the Bases
Whenever working with models, the most important thing to do is to get your paperwork in order before shooting. This isn't a legal article, so I'll simply state briefly that insisting on seeing (and copying) two forms of ID, with one being a state-issued ID, such as a driver license, is the way to begin. If the model forgot to bring her ID with her, then send her home to get it. Don't shoot today with the promise of an ID tomorrow.
It's always a good idea to run a camcorder in the background during the model's interview process, before the shoot, while she's handing over her ID. It's also a good idea to have her hold up the ID near her face (along with a copy of that day's newspaper to show the date), as well as while she's signing model releases. Also, discuss with her the scope of the shoot, and after the shoot, get an impression of her state of mind.
This is an important form of insurance, showing that the model represented herself to be of legal age and was not impaired by drugs or alcohol before, after or during the shoot. And on the subject of drugs and alcohol, while many models might feel more relaxed after a little libation, you're inviting serious legal problems by allowing, knowingly or otherwise, a model to perform when she is not fully in control of her faculties.
And keep this little "buzz kill" in mind: Shooting adult content is only explicitly legal in California and falls under prostitution and pandering laws in every other state. Discuss all of this with an attorney before you begin shooting porn.
Professional adult talent is a phone call away from any of the established booking agents; see the XBIZ Business Directory online for a listing. This is by far the easiest, most reliable way to get performers who know what they're doing and how to do it. It's also the most expensive way, but as they say, "you get what you pay for."
A lot of producers try to recruit strippers as models, a seemingly obvious talent pool. Unfortunately, these girls tend to be less than reliable, to the point where if you want to book one for a specified slot, you'd be well advised to book a second. If they both show up, then bonus for you — not only can you shoot them individually, but you have the option of a nice girl-girl shoot as well.
College town newspapers, alternative papers, swinger classifieds and other such forms of advertisement can be used to recruit amateur "girl next door" and other inexperienced models — the perfect source for the fresh faces that are always in demand. Word of mouth also is a great way; offer current models an "affiliate payout" if they refer their friends.
Of course, there's always the tried-and-true personal approach: "Miss, I'm a glamour photographer, and I'd like you to model for me." The next time you see some hot babe "advertising" it, give that line a shot. You might get slapped, married or find the best model you'll ever have — and perhaps all of the above.
On the subject of getting what you pay for, remember that there are no hard and fast rules — different models will charge different rates, typically on a sliding scale with some acts requiring more money than others. The girl next door doing a solo scene will cost less than a professional porn star in a double anal gangbang.
In the Midwest, talent runs around $850 a day for professional models, $400-$500 per day for semi-pro models and around $200 for amateur models. Some markets command higher prices, some lower, with models' fees fluctuating within and between markets.
Know how much you're willing to pay for a specific model to perform a specific act, and then after thoroughly explaining your needs, ask her how much it would be worth to her. Everything's negotiable.
Avoid profit-sharing schemes like the plague. Pay your model by check the day of the shoot, after she satisfactorily completes her performance – even record her receiving and acknowledging the payment in full as part of your exit interview with her.
Also, don't pay by the hour, pay by the day. The shoot will take a couple of hours, and you don't want to have to deal with the problems that an hourly schedule induces, such as a model maximizing her payday by spending half of it in the restroom. Daily payments are a predictable expense, but feel free to give a model a bonus if she does a great job.
You've found a model, figured out how much to pay her and gotten her to the studio — now what? There are books written on this subject, so there's only so much I'm going to be able to relate here, but the most important thing is to respect the model — you paid to take pictures of her, not to fuck her, abuse her or cause her pain. Or maybe you did pay for all of that and shame on you. Regardless, treating a model — especially an amateur who may be getting her first shot in front of the lens — with sensitivity and respect will not only ensure marketable (even spectacular) images but fewer problems later on. The last thing you want are the cops on your doorstep, holding a rape and assault warrant with your name on it, or someone's big brother on your doorstep, holding a baseball bat in his hand.
Beyond treating the model like a human being, consider her human needs. Ensure that the shooting location offers ample sanitary facilities, provide for refreshments and do whatever it takes to make everyone comfortable. Wipes, condoms, a variety of lubes, toys and other props should all be readily available.
Planning is an important step. Know what you want the scene to achieve and let the model know exactly what you expect of her — the fewer the surprises, the smoother the shoot. Try to guide her actions discreetly; the audience doesn't want to hear your directing skills distracting them in the background, and know when to let the performer control the pace of the action. Do your part as the photographer; let the model do her part as the performer.