Circuit sector is a website by Tomin Markose. He is an electronics and circuits enthusiast. Circuit Sector covers a variety of circuits and projects. I found that I liked this PCB checklist....
Wire-to-board interconnection options from Sullins feature a wide range of sizes and applications
MCC’s TVS series high-power suppressors protect sensitive components from voltage spikes and transients
Evaluation boards that streamline evaluating circuit protection on RS-485 serial device ports