Sometimes self-study is not the best or most desirable training option. Perhaps you do not have the self-structure and discipline to work through 400 page books on your own. Or perhaps you do not learn efficiently through reading. Or, perhaps the certification you are seeking and the skill set you currently have make it very desirable that you get hands-on access to hardware and applications that you do not have at home or work. This is when classroom training should take a starring role.
Classroom training gives you:
But some certification programs don't have such a network. And besides, a training center definitely doesn't have to be "authorized" to be good. The authorized centers become that way by agreeing to conform to various rules and procedures defined by the certification vendor, which often includes defining exactly what texts and materials will be used to train you. This can be a good thing, but it can also be limiting, and more expensive.
Thus there is a fairly plentiful supply of third-party trainers - that is, individuals and companies that specialize in training people to achieve particular certifications. Often this type of training is offered in a condensed, crash-course format called a bootcamp. These do work - I know because I have been to one. It meant intense, long days for 5 days. But combined with self-study before and after, I was able to pass the multiple exams required for MCSE certification within a short time afterward.
Third party trainers can be found through the Internet, as well as in the yellow pages of your local telephone directory.
There is a third source of quality instructor-led training - community colleges. This route offers many of the advantages of the authorized and third-party training, at substantially less expense. Often the training is spread over a longer time period, which can be more desirable for the individual who is seeking to achieve certification while working a full time job, or who just wants more time.
Again, some of the larger certification vendors like Microsoft and Cisco have networks of officially affiliated community colleges, but your best bet is just to contact the technical schools and community colleges near you and find out what they offer.
In some cases, if an employer is seeking to get a group of individuals certified, it's most effective to hire a trainer to come into the place of employment and conduct regular classes on site. This can increase class attendance and reduce time away from work - i.e. opportunity cost.
Instructors can be hired from training centers, or through a local college. Independent trainers can also be found through the Internet, but that will not be terribly practical unless you are going to offer a private boot camp format that takes place over just a few days or a week.
Whichever training methods and certification program you choose, the decision to pursue certification is not made lightly. It requires the commitment of time, resources, and effort. But if you value increased productivity, and a more competitive stance in the marketplace, for the individual and the employing organization, then it's a goal worth striving for.