Technically it's a violation of the EULA. It's less of a violation, (but still a violation nonetheless) if you use a method that does not hack the original media. You can purchase a Snow Leopard CD use Iboot to get it installed, and then use a method like Chameleon or Clover to install the more modern OS up to present previded you have compatible hardware. (that matey, will be the rub for many folks) Don't go into a buisness selling Hackintosh services and you should be safely under the radar.
Please note..
1. Even when working Hackintoshes are fragile machines. The slightest mistake or software update, can wind up with a crippled workstation... If you're looking for a machine that your livelihood will depend on.... do yourself a huge favor and get a real Mac.
2. You're going to get issues using services such as iMessages, Facetime, itunes, and iCloud. Mileage Will vary.
3. Hackintoshes are not a quick fix to get a Mac, be prepared to spend many a man-hour getting the system to work. It's a lot easier than it used to be but it's still not for the technically challenged, nor the impatient.