There is a pretty good seahorse section in Scott Michael's Reef Fishes volume 1. That book is one of my favorite references. Not perfect, but has useful information. One of my favorite authors on fish species.
If you follow Paletta's New Marine Aquarium, you should be able to have a decent seahorse tank.
A few things to keep in mind:
-buy captive bred medium (not dwarf) seahorses which are healthy and trained to eat frozen food
-best beginner species, and a great species anyway, is H. erectus
-feed the right food - frozen mysis (PE or Hikari) are a preferred base diet, but also offer variety if possible
-feed often - seahorses have short, primitive guts - feed at least twice a day
-avoid any stinging corals and giant clams (which will close on a seahorse - I had it happen in one of my tanks)
-in general avoid fish tankmates - many fish can either outcompete seahorses for food, or pick on/at them
-select inverts very carefully - even small hermits may attack seahorses - I use scarlet reef hermits. Peppermint shrimp are good tankmates, and they eat aiptasia.
-watch flow - water should have good flow, but not too strong in the areas seahorses swim, court, rest and eat - I tend to direct flow at water surface and behind rocks
