I just happen to be fascinated by this subject as well. Here are some free .pdfs on lock picking.

Practical Lock Picking:
http://www.rageuniversity.org/PRISONESCAPE/PRISON%20LOCKS%20AND%20KEYS/Practical.Lock.Picking.pdf

The Complete Lock Picking Guide:
https://cdn.shopify.com/s/files/1/0229/9819/files/ukbumpkeys-complete-lock-pick-guide-v1.6.pdf

Improvised Lockpicks:
https://static.webshopapp.com/shops/108892/files/078902441/improvised-lockpicks.pdf

Secrets of Lock Picking:
https://www.withoutakey.co.uk/content/pdf/secretsoflp.pdf

MIT Guide to Lock Picking:
https://www.withoutakey.co.uk/content/pdf/MITLockGuide.pdf

Enjoy!