Any animal that normally lives in water will require water free from chlorination. If you are on City water, be sure to either let the water stand for 24 hours or buy water treatment chemicals designed to make City water safe.

From Teresa:

We have a lot of experience with keeping reptiles and amphibians that were caught outdoors.  I've never had any problem with salmonella. 

• Toads:  These are very easy to keep, quite tame, easy to feed and have a surprising amount of personality.  The larger the toad, the easier they are.   They will eat worms, ants and just about any bug that moves.  They can also be trained to eat raw hamburger, bologna, etc.  of the end of a broomstraw if you twitch it like a bug.  When I was a kid I trained a toad to hop over to my hand and take raw hamburger right out of my fingertips.   Last year my son caught a huge toad in Vermont and brought it back down to CT.  It was so tame after about 3 days, even after the long drive and lots of handling, that the toad actually was catching flies out of the air while my son was holding it.  Just about any container will do for them, just be sure they have some water. 
• Tadpoles:  Make sure they have something to eat, which in nature is usually algae.  Cooked spinach is one possibility.  I use a bubbler in the tank, but it's not always necessary.  As soon as the tadpoles get all four legs turn them loose. 
• Amphibian egg masses:  From vernal pools in the spring, they are usually either the eggs of spotted salamanders or wood frogs (they look like a mass of clear or green jelly, except toad eggs are in long strings).  Aerate the eggs in water until they hatch.  If they turn out to be tadpoles, see above.  For salamander larvae, they will need to eat very small animals like mosquito larvae (they will eat huge amounts of these).  If you can't feed them, let them go in the same place you found the eggs.  Do NOT let them go in a lake or stream with fish, because they will all get eaten up.  One they loose their gills they will be ready to move out of the water.  I would turn them loose at that point because it will be hard to get really tiny bugs or worms to feed them.
• Spring amphibian migration sampler:  For one night each spring there is a mass migration towards the vernal pools that many amphibians breed in. This will be the first rainy night after the snow melts in March.  Drive along quiet roads and look for "hot spots" near wetland, especially in new developments where they haven't all been wiped out yet.  In spring of 2005 in half an hour we counted 52 woodfrogs, 4 tiny spring peepers (undoubtably missing many more because they are hard to see), and 3 spotted salamanders in our headlights.  We kept one of each for a few days (click on photo to enlarge).  The spring peeper, a male, began calling while in the house. That tiny frog was loud!
• Freshwater aquariums: Sunnies and other freshwater fish make interesting pets.  They can be taken care of like goldfish (be sure you know the basics of aquariums before setting up a tank - there are issues of ammonia and nitrate toxicity).  Sunnies are surprisingly aggressive to each other.  You can also add freshwater clams and crayfish. Crayfish will eat just about anything and do a good job of cleaning up the bottom.
• Long Island Sound Aquarium:  Room-temperature water, with salt water that is less salty than a normal salt-water aquarium.  For more info see the Long Island Sound Biotype Aquarium at  http://www.borntoexplore.org/aquarium
• Garter snakes: I had a snake as a kid and fed it tadpoles (they swam in a dish) and earthworms.