MyVestaCP Debian Fork (Recommended)
MyVestaCP Website & Forum
MyVestaCP Installation & Tutorial
MyVestaCP Knowledge Base

Original VestaCP (Caution: not regularly updated)
VestaCP Website & Forum
VestaCP Installation & Script 
VestaCP Support Documentation

HestiaCP (Administered by previous Admin of the original VestaCP)
HestiaCP Website & Forum
HestiaCP Installation
HestiaCP Documentation