I have done some herping in north eastern Illinois, but dont recall finding any salamanders. But here are some tips:
cruise roads on warm rainy nights from Feb to March.
put minnow traps in fishless ponds.
seine larvae in the fall.
Of course , there may not be too many salamanders in your area. What type of salamanders are you getting in your window wells?
I am not in northern Illinois during the spring, but if I were , I'd be road cruising. I ususlly make it up that way during summer for snakes. Do you know any good places for Thamnophis radix?