It depends... There are resources available via trade schools, seminars, colleges, community colleges, etc. Check around your local area. PSW is great for all sorts of info. Internet: There are many, many online articles, whitepapers, manufacturers websites & discussion groups.
Mentorship can be an invaluable tool. Is there anyone who can "show you the ropes" and let you practice, while they guide you?
Here are some books:
Sound Reinforcement Handbook -- by Gary Davis, Ralph Jones;
Guide to Sound Systems for Worship/290243 -- by Jon F. Eiche
Sound System Engineering -- by Carolyn Davis, Don Davis
JBL Audio Engineering for Sound Reinforcement -- by John Eargle, Chris Foreman;
Basic Electricity -- by Nooger Van Valkenburgh
Master Handbook of Acoustics -- by F. Alton Everest