How to take care of a painted turtle

Question
I found a painted turtle on the Heritage trail.  I stopped and put it in my basket and took it home. I looked up about them on the internet them but I still need help. I know he is a boy because he has a wide tail and long claws. I have him in a HUGE cardboard box. Do they carry any bad things? How can you tell? Are they life threatening? What are there favorite foods? Do the have to be in water or can you just put like a dog bowl? How long can they live? Do they bite? How can you tell how old they are. Should I get water from a lake or house water? Which would make them happier? Do they like to be held? How much will they eat a day? how big should their tank be if I need it? Will they give any bad things to other animals?      Thank you
                               M

Answer
I always suggest releasing wild-caught turtles because of the trouble it takes to set up a good habitat.

Wild-caught turtles can carry Salmonella, which is not really a big deal, and internal parasites, which is only an issue because the parasites can cause health issues when the turtle is stressed- as in captivity.

The rest of your questions would be best answered by a good site like this: http://www.austinsturtlepage.com/Care/caresheet-midland_painted.htm

If you have any further questions after reading this, please let me know.