I would argue that you still need to take care while cycling, whether its a turtle or a fish. while in fish, the most sensitive area affected by ammonia and nitrite is the gills, turtles do have mucous membranes that can be affected by these (most notably, the eyes). they just deal with it better, so may not show signs of stress or discomfort as readily as fish.
Care for cooters is similar to most basking turtles. You'll want a talk you can fill up as much as possible for swimming space, and something like a ZooMed floating turtle dock will be fine for a basking area. A basking lamp (could be a regular fluorescent bulb in a clamp light) should keep the basking area around 90 degrees. For hatching turtles, you can keep the water temps at 76-80 degrees. You'll also want a UVBspecific fluorescent light over the basking area. There are some mercury vapor bulbs that supply both heat and UVB, but they are quite expensive (70ish dollars). You'll definitely want to overfilter the tank and keep up with water changes, even a small turtle can foul a tank pretty quickly, especially since they will eat lots of meaty foods early on. You can also keep leaf lettuce or plants like anacharis floating in the tank pretty much constantly for the turtle to munch on at any time. I prefer aquatic plants to lettuce as if they aren't eatedn, they won't foul the tank up, they just grow.
