Of the locksmithing (as opposed to lock picking and bypass) books I have, the one that Squelchtone suggested is probably the closest to the "Bible" of locksmithing. Phillips also wrote
Locksmithing http://www.amazon.com/Locksmithing-Second-Bill-Phillips/dp/0071622756/ref=sr_1_11?s=books&ie=UTF8&qid=1452736682&sr=1-11 and
Master Locksmithing
http://www.amazon.com/Master-Locksmithing-Experts-Intruder-High-Security/dp/0071487514/ref=sr_1_12?s=books&ie=UTF8&qid=1452736682&sr=1-12. The
Locksmithing book I have, and it seems like a good introduction to locksmithing (I'm not a professional locksmith, so I my not be the best judge). The sections on access controls and alarms are not that great, in my opinion. The
Master Locksmithing book I do not have (yet), reading reviews on Amazon there are complaints that he used a lot of manufacturers booklets for filler and the safe and vault chapter is thin. Phillips does tend to pad his books with vendor booklets, but that can be a good thing if you need to know how commercial hardware works.
A couple of other books I have that you might find used, one is
Locksmithing by Rathjen. The section on alarms is good, although it does not have the new stuff. Overall a solid book with a good section on master keying, interchangeable cores, and running a business. But, he did not include anything that could assist a criminal in the book, so no picking or impressioning. The other book I have is
Practical Course in Modern Locksmithing by Whitcomb Chrichton (1971 edition). It is in a distant last place compared to everything else. It covers most of what Rathjen does, only maybe circa 1950 even though it was supposedly revised in 1971. Unless one is interested in the history of locksmithing or something like that I would recommend the book.
Another type of book you could look for would be the course booklets from a correspondence course that someone else took. A lot of people take the Foley-Belsaw course (and courses like that) and never go into business. Later on the stack of booklets go on eBay. Last week a full set of the Foley-Belsaw course books sold for $40 or thereabouts. Wish that I had bid on it. There is another one on there right now
http://www.ebay.com/itm/Belsaw-Institute-Professional-Locksmithing-Course-Book-/291640378716?hash=item43e71f055c:g:Vk0AAOSwgQ9VsYso, although it looks like an older copy. It seems like a new set of Foley-Belsaw locksmith booklets shows up on eBay about once a month.
There are some DVD courses, but I have no first hand knowledge of them. Regarding video, there is a youTube channel that has some basic locksmithing
https://www.youtube.com/playlist?list=PL6FAA070778F1219E. One website that I find interesting is
http://www.gaterslocksmith.com/blog/, it is a blog by a locksmith in Florida, it really brings out that locksmithing is not just picking locks or repining locks all day. It is basically a few dozen well-photographed jobs with running commentary from a professional locksmith.