I actually found a equine dentist in my area (didnt think I would-rural area) that have great prices! He doesnt even sedate usually! The site does say that I can get anesthesia from my vet (that is questionable to me.... I don't see that happening)....
You can't check teeth just by sticking your hand in their mouth without a speculum that will allow you to put your arm all the way in to your elbow without the horse closing it's jaw. The teeth that most often need attention are the molars, or the last set of teeth. You can take a flashlight, hold their tongue to the side and look. You are looking for sharp points, grinding surfaces that are not flat, ulcerations in the inside of the cheek, packed hay wads, longer teeth on one side or arcade. Having a second set of hand to hold the tongue can help but still not easy to do.