The information contained in these directories is old stuff and unlikely to be effective now as it was collected near thirty years ago.
Probably pointless, but its collected here for archive and educational purposes only.
Many of the websites its drawn from no longer exist, and would have be accessed via the Internet Archive.
A lot proved fruitful for my career administering Unix and Unix like systems (including Linux and FreeBSD).
Indeed it gave me a career (for a while)! Always self taught, not having the background of a computer science degree.
A retro lab of vintage equipment to revisit some of the stuff decades later would be kind of fun.
Intrusion Detection: https://weycrest.net/information/infosec/info/IDS
Operating Systems: https://weycrest.net/information/infosec/info/OS
FreeBSD: https://weycrest.net/information/infosec/info/OS/FreeBSD
Linux: https://weycrest.net/information/infosec/info/OS/Linux/
OpenBSD: https://weycrest.net/information/infosec/info/OS/OpenBSD/
Sysadmin: https://weycrest.net/information/infosec/info/admin/
Authentication: https://weycrest.net/information/infosec/info/authentication/
Detecting backdoors: https://weycrest.net/information/infosec/info/backdoors/
BGP for beginners: https://weycrest.net/information/infosec/info/bgp4/
Buffer Overflows: https://weycrest.net/information/infosec/info/buffer_overflows/
Cracking: https://weycrest.net/information/infosec/info/cracking/
Encryption: https://weycrest.net/information/infosec/info/encryption/
Exploits: https://weycrest.net/information/infosec/info/exploits/
Firewalls: https://weycrest.net/information/infosec/info/firewalls/
Forensics: https://weycrest.net/information/infosec/info/forensics/
Hacking: https://weycrest.net/information/infosec/info/hacking/
Honeynet: https://weycrest.net/information/infosec/info/honeynet/
ICMP: https://weycrest.net/information/infosec/info/icmp/
Miscellaneous: https://weycrest.net/information/infosec/info/misc/
P2P: https://weycrest.net/information/infosec/info/p2p/
Phrack: https://weycrest.net/information/infosec/info/phrack/
Programming: https://weycrest.net/information/infosec/info/programming/
Protocols: https://weycrest.net/information/infosec/info/protocol/
RFC’s: https://weycrest.net/information/infosec/info/rfc/
Security: https://weycrest.net/information/infosec/info/security/
Sniffers: https://weycrest.net/information/infosec/info/sniffers/
Tools: https://weycrest.net/information/infosec/info/tools/
Topology: https://weycrest.net/information/infosec/info/topology/
Wireless: https://weycrest.net/information/infosec/info/wireless/
“No Bugs” (Bill Gates) : https://weycrest.net/information/infosec/info/nobugs.html
Good Jargon: https://weycrest.net/information/infosec/info/good-jargon.html