Sports-A-Rama used to hold them in conjunction with the local area rec parks. I don't know if there are any for the travel ball levels. Someone should start.......
We will hold some coaching clinics soon at our facility in Canton. We will advertise on this site when we are further into the construction and more past the political hurdles :) Will be ready by Fall for sure though...
I have been involved with 5 or 6 over the last 10 years with nationally known speakers hosted by some top organizations. Some were sponsored by organizations and were free and some charged a fee. They all did not get the attendance levels to warrant the effort. Of the ones I was involved with only Ripken Baseball has tried more than once.
FCA does a good clinic every January for youth coaches (geared mostly to travel coaches). They usually have local high school coaches as well as college coaches and current/retired professional players. They have also had travel umpires there to discuss rules, etc. I think the link to their website is georgiafcabaseball.org. I've been a couple of times and always gotten a lot out of it.
NGBSA has annual clinics hosted by the local high school coaches. Also require coaches take an online coach certification course every three years. After a certain number of seasons you certainly acquire a good base of knowledge on coaching youth baseball. But you can always learn something new and continue to improve your abilities to coach youth athletes. One great resource I've read over and over is The Mental Game of Baseball, by Dorfman. It's been around a long time and i'd bet if you polled all MLB players most would say they've read some part of it. Great book.