Welcome to Michael D. Bateman's Links Page (some of my favorite sites.
One of my current favorite sites (which also links to the some of the other sites):
Red Team Training Reviews
Pentester Academy
k>fivefour
k>fivefour Battlegrounds
eLearnSecurity
CyberWarFare
Offensive Security
Sektor7 Institute
Zero-Point Security
HackTheBox
PentesterLab
Silent Break Security
Lab of a Penetration Tester
Active Directory Security
Synaack Red Team
SANS
SANS Holiday Hack Challenge
SpecterOps
Millennium Corporation
more soon