Ok, first of all what Vince V. said is true. Recording studios are generally a bad investment, especially if all you're offering is recording services. There's tons of competition and honestly, not THAT MUCH demand. I personally would never waste my time and money trying to run a public recording studio. A lot of people think if you buy the equipment and rent a building, the business will come. BAD assumption!
Now, about what Filthy_Rich said... "Hip hop recording" isn't really its own beast and there arn't any "hip hop specific" recording techniques. Any good recording engineer who knows his room, knows his equipment, and is will to put in atleast some effort into his work should be able to adapt to what you want.
If you really want to learn, the best way is to start hanging around studios and see how they operate both in the control room and in the office. Schooling can teach you basics, maybe a little more if you're lucky. Hands-on learning from a solid engineer will teach you tons that you'll never get from a classroom. Learn from people who do it for a living as opposed to cats whose only "experience" is limited to messing around with their 'bedroom studio'.
One last thing... There is no crash course. It takes a long time to learn this stuff. If you (or whoever) is serious about getting into it, find an engineer who already has a significant amount of knowledge and experience doing this kind of work and put him on salary. Unsatisfied clients WON'T be coming back and certainly won't be recommending your studio to anyone.