I have a question about timing of CLEP exams. My son just graduated HS this past spring and is taking some time off before going to college. After finishing my degree by testing (today if I passed) out of my last few courses I am encouraging him to START his college career with testing. I know a few things about it.

1. Many Universities won't accept general CLEP exams.
2. Almost all require 30hrs resident
3. IT'S WAY CHEAPER TO TEST THAN TAKE A CLASS

My biggest questions are about timing. Should he wait 'till he actually enrolls? Is there an "expiration date" on tests? Any constructive advice will be greatly appreciated.