I have used some online courses, and, to be honest, was not impressed. I'll probably use some more some time, for lack of anything better.
Best bet is be willing to travel a bit to hit various ASCE or other organization's short courses, seminars, etc. Fly to LA or Dallas or wherever, spend a couple of days, and it's almost like a little vacation.
I would recommend taking college or university courses, assuming that they qualify for continuing education. You receive credits that go on a transcript when you take a college course and they are permenant. I also think the classes you take are more valuable than many continuing education programs.
Certainly, civil engineering level undergraduate or graduate courses are one option. Another option - one that is much easier - are community college classes that relate to civil engineering. For example, I'm taking a bunch of classes in water and wastewater treatment. They're geared toward a maintenance technician (so they aren't hard) but I've learned a lot of hands-on practical knowledge.
I've had good success with redvector. They keep up with the records as well. There are some good multi-part courses and they are approved in most states.
