well, if you get them while young it would probably benefit you to have a little land. It also depends on how many you're getting. If you're getting more than two I would think about getting a 20 gal. If you want to separate the land from water, which you will need to, go to home depot and have them cut you some Plexiglas (measure the width and height before you have them cut and they WILL cut it for you). Setting up land has a few more steps than throwing some dirt in there.
http://www.blackjungle.com/basics.htm
Also, the substrate I know to work the best for my JFBs and my friends tiger salamander is coconut substrate, BedaBeast. You find it in a block which you will have to make into dirt by soaking it in water. (Petsmart)
The water side will need to be set up before you get your pets, at LEAST a week before. You will need water test kits for ammonia, nitrates, and nitrites, they are cheap from what I recall and they last a while. You will need to do some research on cycling the water. I would suggest starting with some small ghost shrimp, even whisker shrimp which are a bit more aggressive and larger, I have never had a problem with these fellas. Depending how large your water area is I wouldn't go more than two and they cost.... like a few cents each... lol
Plants, java moss/fern, pathos, and anubias are hardy, don't require much light, and grow fast. Java moss and fern are strictly aquatic as well as anubias. Pathos can grow in and out of water and it can grow fast, so just keep up with where you want the tendrils to go and you will have a luscious creeper filling your tank. If you can find anyone with a mother plant (pathos) you can simply clone by taking clippings and placing them in water and waiting for some roots to sprout. (If you look at the long creeping stems you will find there are sections and at the beginning and end of each section has small brown nubs coming out of it, these will be future roots; just clip right before so you still have these nubs at the base of your new plant and place it in a glass of water. You can do this a few times to a have a few clippings just not too much! Roots will begin to grow within the first few weeks, once they reach about 2 inches long and have begun to develop even more small roots off of their original roots, this is the time you can plant them into dirt.) Plants are hugely significant in a SELF SUSTAINING TERRARIUM.
LARGE substrate is a plus; you are in danger of compaction if you get them something they can put their mouths around and they can stuff some big things in themselves. SO, keep that in mind, but also realize that they deal with small substrate and dirt in the wild... so they are also capable of being healthy and strong without your help.
When everything is set up, settle and wait, things WILL be fine as long as you don't mess with too many chemicals around and in the tank, if you have a cool environment, and patience the small ecosystem will take care of itself. Plants will introduce healthy bacteria and microorganisms into your tank and the longer you let it set the more time it will have to do it's thing. Test the water once a week. Make sure your tank has a Perfect medium of moisture, too much spraying can cause fungus on the soil or wood you put in there, letting it get too dry while your pets are terrestrial can cause some shedding problems. I would suggest a water dish on land.
You can get creative when it comes to hiding places for them, they like to hide under logs and in lots of plants. Keep researching, and consider getting your newts from this forum. I once went to a shop which I THOUGHT was a really well care for shop and after about a month, slowly, one by one all three of my CFB died ... I'm pretty sure they had parasites and too much stress to cope with life at all. None of them ate and I had to watch them pass... And believe me that experience would turn you off of this hobby faster than acid being thrown in your face. So first find a reputable breeder, and then ask them what kind of set up they have for the babies you will be receiving.
Just keep asking questions.
Sara
