here is the best place to start. do lots of reading before posting any questions as some of the members get grumpy answering the same basic ?'s over and over but its about the best single source of info.
here is another link with basic info
Saurian Enterprises info page
dart frogs for the most part are simple to keep. a wet, planted tank with plenty of hiding places, normal room temps, regular feeding and they thrive. as i stated before, for most such as Tincs and azureus the price of the frogs has more to do with the time put in to raising them than actual difficulty or rarity. generally its advised to stay away from thumbnails to start with as they are quite a bit smaller and there for slightly harder to feed(springtails and fruit flies) where most of the tincs and azureus can take small crickets if needed along with the smaller prey. leucs are a great first dart, they do well in groups, are generally slightly cheaper than tincs and are quite bold. auratus are generally cheaper but they tend to be shyer. with Tincs and azureus two females SHOULD NOT be kept together as adults as one will probably be bullied and die from the stress. azureus are generally shy when young and yah dont see them much till they are older and than they becom quite bold. tinc(atleast my 2) are jumpy and dive for cover when startled but are out quite abit and i see them all the time. one of mine is generally found plastered to the front glass of the tank watching for me to come over and feed them.
thats all the quick, general pointers i can think of off hand, ill answer any questions yah want to think up as best i can