O'Reilly Online Learning is a fantastic online learning portal, with books, videos, and live interactive instructor-led learning for multiple IT subjects.

Temporarily (until July 6) they're giving out free access to those with .gov domain email addresses.
https://www.oreilly.com/online-learning/government-free-access.html

FYI, this isn't for OReilly auto parts, this is Tim O'Reilly's IT-oriented O'Reilly Media.