Long ago, before we had the internet, one of the books talked about in certain circles was “The Soldier’s Handbook” by Anthony B. Herbert. This included information on how to make lock picks! It also came with a hefty price tag, so only serious/rich readers could dream of obtaining a copy. Wealthy people never misuse information, of course.
The Soldier’s Handbook has some interesting sections, but in retrospect I am glad I never tried to make lockpicks from the designs given. Here is a scan of the relevant page. Looks like a batarang, a half-ball, half-snowman, a full diamond and what look more like dental tools. I would not have gotten far! The instructions on how to use lock picks, and other entry techniques are not that bad, in fairness.
How lucky we are now! There are plenty of good sources of information on how to use lock picks, including, I hope, this blog. Companies such as UKBumpkeys and WithoutAKey offer good quality picks at reasonable prices. And if you are really on a budget there are Chinese-made sets from companies such as Goso and Klom. Not so nice but they are good for learning.