KinkyClover.com
Clover offers a free downloadable 9-page PDF called "A Guide for Rope Bottoms and Bondage Models" and much more.
RemedialRopes.com
A must-visit site focusing on risk awareness for rope bondage bottoms and tops.
FetLife.com
• Groups: Rope Writings Library, Rope Bottom's Roundtable, Ask a rope bunny, Riggers and Rope Sluts, Rope Incident Reports, Rope Bondage
• Twist Ties' comprehensive collection of resources for rope bottoms
• Guilty's note on bondage safety for bottoms
• Kaizen's list of dedicated rope tying spaces worldwide
Anatomy for Rope Bondage video by IPCookieMonster & co.
Nerve damage study by Esinem
Nerve injury reference card by Frozen Meursault
Info on the brachial plexus nerve branch and exercises to help in a takate-kote by Sin
Neural glide exercises video for ulnar, median, and radial nerves by Dr. Jo
Femoral nerve glide exercises video by Rehab My Patient. This linked one is the first of a series.
Long and short, by Jay Wiseman
YouTube.com, Evie Vane channel
Fee instructional videos on getting tied up for fun.
Advice Sheet for rope bondage bottoms and tops and Guide to Evaluating a Hardpoint for Suspension
By Topologist. And yes, as a bottom, it's in your best interest to learn how to evaluate a hardpoint!
Not free, but has lots of rope bondage video tutorials and much more. Check out "Bombproof Bottoming: Suspension from Sub's Side," with Tifereth and Cannon.