This is not a suggestion but questions, about some things that I find pertinent to get information on when getting into this hobby!
Threads or information about:
- how to measure current draw (multimeter, clampmeter, …)
- how to measure parasitic drain (multimeter, clampmeter, …)
- how to measure lumens
- how to measure candela
- differences between/properties of the main materials of flashlights: aluminium, brass, copper, titanium, stainless stell
About internal threads:
LEDs & Other Stuff - (Reference Guide), by CRX
Flashlight User Interface Cheatsheets, by CRX