My friend, there is so much to tell you. Far more than there is space to write, in fact. If I were you, I'd go the library, pet stores, and book stores and buy all of the turtle keeping books that I could find. I's stick to year 2000 and higher versions. Some are better than others, but you need a base of knowledge now, so read as much as you can.
This website has many species-specific care sheets for you, so look around. Your painted turtle, map turtle, and softshelled turtles may come from different habitats, depending on the exacty (sub)species that you have. Therefore, their care requirements may be quite different. Look for as much specific information as possible. There is a great website for turtle identification, which usually contains pictures of hatchlings and juveniles. It is www.chelonia.org. Go to species gallery, by genus, and look at the Chrysemys, Graptemys, and Trionyx(or Apalone) genera. Good luck. In the meantime...here's my two cents; clean, dechlorinated water, a variety of live food items, UVA and UVB lighting, smooth stones for basking, water relatively shallow, did I mention clean water, and lastly read your books BEFORE doing what the people at pet stores say. Unfortunately, many just don't know much about turtles.