You should consider using T-shirtfourms.com

When I've needed folks I take three approaches.
1. Let others in my affiliate (not other printers) community know a position is available. You don't want to be poaching workers from local shops.
2. I find the 'grinders,' meaning those willing to work hard but underutilzed, often peruse Craigslist.
3. LinkedIn has proven an exceptional resource for skilled workers.
Now, don't underestimate what is available through the schools in your area. I have found offering internship positions keeps my pipeline full of candidates. Stay in touch and in a few years when they get some managment expereince, you can take measure of they happiness IQ.