Here is a excellent site for PID Simulators there at the bottom of the page of this link click on the simulator you wish to explore for example
PID Loop Shaping
PID Basic
PID Wind Up
etc
I would also advise you to do a little reading if have no experience with PID control as you have to adjust parameteres in simulator it would be benifical to know what your changing and have some idea what should be happening.I hope its of some help.