Opportunity is missed by most people because it is dressed in overalls and looks like work. - Thomas Edison
Books that present the whole process from beginning to end are perhaps the best way to get up to speed. They won't really teach you everything you'll ever need to know, but they can give you enough of an overview that you'll know what's being talked about elsewhere. My introduction to screen printing was Fresener's "How to Print T-Shirts ...for Fun & Profit." I've learned a lot since then (still learning all the time, actually), but that book got me into the pool, so to speak.