First there is the most common means of learning how to train your dog; group classes. Almost all communities or large pet shops offer this type of training. It can be good depending on the trainer and their specific groups offered. The teacher/trainer may or may not be experienced so it is best to ask around for some recommendations; anyone can be a trainer but you want to learn from someone who is knowledgeable and experienced. The good thing about group classes is that your dog learns to work around other dogs.
Next there is private in-home training; this is my specialty although I started out teaching group classes. I like the one on one; undivided and personal attention given to each dog and guardian through private training. You hire and trainer and they come to your home to teach you to teach your dog. Just like anyone other profession there are good and there are bad trainers. I've heard a lot of horror stories; so again, ask around.
Private training should be flexible; working around your schedule. You pay more for it but in my opinion it is more than worth it. You have a professional trainer at your disposal; it's all about you and your dog. Any problems you are having are dealt with directly and being that it is done in your home it is easy for a trainer to see the problems you are having with at home.
Lastly and definitely not the way I would go is to ship your dog off to a trainer. There are different levels of this type of training; different types of services. Some trainers will have you drop your dog off weekly for training; you don't stay, you don't watch. Then there are trainers who take your dog for weeks or months at a time; again, not a fan. Now in all fairness there are good trainers that offer these types of services and you want to make good and sure that you can drop by at anytime or watch the training.
The problem I have with this type of training is when you are not allowed around; you cannot watch, you are not welcome to visit. This alone should send up a red flag. And I've had personal experience with the aftermath of some of these trainers. I have been called in several times to undo what has been done to a dog; and the guardian unfortunately has no idea what happened. If one of these facilities has an open door policy great; check it out. Find out where your dog will live, what they will eat, how often they will be trained etc. But; if for some reason you are not allowed around I'd definitely pass on this one.
The other issue I have with these facilities is that I believe strongly that you should train your dog; this is a bonding time, a valuable learning experience. I have taken dogs into my home to give them a kick start on their training; I completely allow those guardians to drop by anytime and ask all the questions they want. Also their dog lives in my home as one of mine; not in a kennel. Sometimes this is difficult on me as I tend to get attached quickly.
So which ever type of training you decide is right for you and your dog; ask for references. Talk to people; find out their experience with particular trainers. Just because someone says they are a trainer does not mean that they should be your trainer. Many trainers have little experience and cannot help with issues; so if you are having specific problems one of these guys or gals isn't going to be much help to you. Do you research.