JetPack Software https://developer.nvidia.com/embedded/downloads
Developer Forum: https://forums.developer.nvidia.com/c/agx-autonomous-machines/jetson-embedded-systems
Jetson Hacks: https://www.jetsonhacks.com
Jetson boot from USB: https://www.jetsonhacks.com/2019/09/17/jetson-nano-run-from-usb-drive
GPIO Pin Descriptions: https://www.jetsonhacks.com/nvidia-jetson-nano-j41-header-pinout (its pin compatible with Raspberry Pi IO connector)