@21m
Bitcoin Core - primary bitcoin software, website created by Satoshi!
Nakamoto Institute - great resources, all Satoshi’s posts
Bitcoin.page - comprehensive info for all knowledge levels
Saylor Academy Bitcoin Course - FREE excellent 101 online course
We Run Bitcoin - Matt Odell’s guide to running btc, multisig
Bitcoin-Intro - a good starting place
CaseBitcoin - best cases for owning btc
BitcoinQnA - great FAQ for BTC
Bitcoin-Only - another great set of info
BitcoinPrivacy.guide - learn how to use bitcoin more privately
Bitbo - Bitcoin Dashboard
Clark Moody - Bitcoin Dashboard
Buy Bitcoin - Square Cash App
Buy Bitcoin - SwanBitcoin
Buy Bitcoin - River.com