It sounds like you have a more complicated job/business going on than I did, but here's what I ended up doing....
I had a lot of yahoos come through my place who knew a lot about food but who didn't give a rat's behind what I was trying to accomplish with my business. I also had a few weirdos come through who didn't know jack about food, but who could "work any time" (or steal anytime). Then... there were the best ones - students who were on their way to something else eventually (whether it be food or whatnot), but who were honest with me from the beginning about what they needed in a job from me and who remained honest in what they promised to provide in return.
Believe it or not, I found that one of the best ways to find people like this is in the every day application. Give everyone, resume or not, an application to fill out. And only call back the ones that dot every "i" and cross every "t" on the application. No exceptions.
When I started doing this, I only had one more bad apple. And if I had taken more time to talk to him before hiring him, I probably could have avoided that situation, too.
"'If I watch out for rocks
With my eyes straight ahead,
I'll keep out of trouble
Forever,' I said."
Dr. Seuss, "I Had Trouble in getting to Solla Sollew"