[lcstorc]

Great advice given so far but of course I have to add my 2 cents.
IMO there is no such thing as a beginner seahorse. If you have had saltwater tanks or reefs for some time and are now wanting to branch out to seahorses then that us a different story.
These animals are wonderful but are not "easy"
First of all listen to Matt on the temp. They must be in a cool tank. I have tried and tried to keep them in a tank at reef temperatures and it just doesn't work. I have sworn I will not do that again to these special animals. I have to figure out a way to keep my temp down on the pony tank before I even think about it. (Well I do think about it but won't do it again. I promise.)
They are best kept in a species only tank for 2 reasons. One is because they eat so slowly. If you have fish etc in the tank as well they are very likely to steal the food from the ponies. The other reason is agresiin from the other fish. Again the ponies move slowly so if somebody is picking on them they have a hard time getting away. They can be kept with some of the more docile fish particularly the ones that stay on the bottom. For example I have not had any problem mixing them with jawfish and a clown goby. Right now there is a yellow watchman goby in my pony tank and he will probably stay there when I get new ponies since he is another passive bottom dweller
Last and most important is to look for captive bred or tank raised ponies. IME is is very difficult to switch them from live to frozen food. If you get a captive bred or tank raised they should already be used to the frozen food. (Watch the lfs feed them before buying to make sure.) If can be very stressful on you and the animal to convert them so I don't even try it.
The very last thing is listen to Matt. He really knows his ponies and how to care for them. Had he been around when I initially tried to keep them I am certain I would have had better success. I am thrilled he is here for the next time I attempt it.