what i would do (and did), is build one. get "the hang of it". then you can put a second together while you are learning about the newest additions. i started with white's (i now have 6). as i was learning how to care for them, i built a second enclosure for red eyes. research each type of frog you are interested in first. research, research, research. unfortunately, unlike fish, or a dog, frogs are not a "pet" where you can just throw them in the tank and say "Hey, look at my frog!" these are extremely informative places to start :
http://www.frogforum.net/tree-frogs/...caresheet.html
http://www.frogforum.net/tree-frogs/...caresheet.html
remember, some frogs live quite a long time, like white's. so expect a long term relationship with your starter frog
oh, and i cannot stress this enough, take your time, you have the rest of your life to decide all this and build homes for frogs. rushing into could (but not always) lead to catastrophic circumstances. and when you are ready, make sure you do everything you can to purchase Captive Bred red eyes good for the environment and better for the frogs