Going to try to keep this updated.
Learn Windows PowerShell in a Month of Lunches (Youtube) - Companion videos to the famous book
p3nt4/PowerShdll - Run PowerShell with dlls only. Does not require access to powershell.exe as it uses powershell automation dlls.
nullbind/Powershellery - GetSPN and other things
Empire 101 - Empire Introduction from official documentation
Powerview repository - contains documentation and how to use Powerview
PowerView-3.0-tricks.ps1 - Powerview tips and tricks from HarmJ0y
Bloodhound node info - Bloodhound Node info explanations
Lay of the land with bloodhound - General Bloodhound usage guide article
Lazykats - Mass Mimikatz with AV bypass (questionable)
eladshamir/Internal-Monologue - Internal Monologue Attack: Retrieving NTLM Hashes without Touching LSASS
Invoke-Portscan.ps1 - Invoke-Portscan is a module from Powersploit that can perform port scans similar to Nmap straight from Powershell.
Walking back local admins - Finding local admins in AD
HarmJ0y - roasting-as-reps - Article about Kerberos preauthentication
HarmJ0y/ASREPRoast - Project that retrieves crackable hashes from KRB5 AS-REP responses for users without kerberoast preauthentication enabled.
SShuttle - SShuttle creates an SSH tunnel that works almost just like a VPN
SANS Pentest Blog - Using Amazon AWS EC2 for C2
lukebaggett/dnscat2-powershell - Powershell implementation of dnscat2 client
C2 with dnscat2 and powershell - dnscat2 can be used with powershell for working over DNS to hide C2 activity
DNS tunneling - How DNS tunneling works
SharpShooter - SharpShooter can create payloads for many formats like HTA, JS and VBS
DCShadow - DCShadow, attack technique to create a rogue domain controller
Ruler - Ruler can interact with Exchange servers remotely
Applocker Case study - Breaking out of Applocker using advanced techniques
Bypass Applocker - List of most known Applocker bypass techniques
MS - Securing privileged access - Reference material for securing admin access in AD
MS - What is AD Red Forest - Red forest design is building an administrative AD environement built with security in mind
The Eye - Official MSDN ISOs for all OSes
Automatedlab/Automatedlab - Automatedlab is a project for building a lab environment automatically using Powershell.
Building a lab with ESXI and Vagrant - Big article from this book about building a lab using ESXi
Mini lab - Small article from this book about creating a small lab for practicing things like Responder
OSCP Survival Guide archived - contains a ton of useful commands for enumeration and exploitation