This is another pet peeve. The owner gets the perk of going to a show and taking in seminars and then the responsibility of passing along the technical information. Your key printers will become loyal employees if you let them tag along to the next show and let THEM ask the questions and see and hear about the newest techniques. From how long to expose screens to what quality standards you expect, to how long you flash cure - this book is what new people and your regular people will use as the standards. The Screenprinting and Graphic Imaging Association in Fairfax, Va, has a training center called the Screen Printing Technical Foundation.
Most suppliers offer open houses and training.
Many of them will also train on-site if you are a regular customer or if you purchase your equipment and ink from them. The only problem with supplier training is that it is usually very commercial and often is really just a chance to pitch products. The U. S. Screen Printing Institute offers video training course that range from professionally produced tapes to seminars that have been video taped. Either way, you get more information than if you did nothing at all. Start your video library and make these part of your regular sessions.