These symptoms would warrant keeping your children at home. Going to the doctor's office raises the slight risk that, while sitting in the waiting room, your kids will pick up a worse bug.
My insurance includes a Nurse Hot Line which I can call for advice. That's nice. Calling your pediatrician's office is great too, not just because it is free, but because you might get some information which would help. For instance, "please make an appointment if your child develops a fever" or "we are seeing a lot of kids with these symptoms, if you see no improvement in 3 days, please make an appointment" (or however number of days).
Otherwise, I like how the previous respondent worded their response. Push the liquids, wash hands often, and let your mothering instincts guide you. (For instance, if you can tell that your 4-yr-old is coughing in a hacking kind of way and it sounds like it is coming from his chest, that would warrant getting his cough checked out and make sure your child doesn't have any fluid in their lungs.)
This, too, will pass. Good luck.