Here’s where I go to learn new stuff.
https://dba.stackexchange.com/ – Got a question? Ask it here or see if someone else has asked it. Set yourself up and account and have a go at answering other people’s questions.
https://www.brentozar.com – Don’t think he needs an introduction
https://sqlbp.com/ – best practices guide by several MVP and MCMs
http://www.midnightdba.com/ – Lots of free tutorials (check out the PowerShell ones in particular)
http://www.scarydba.com/ – SQL blogger/MVP
https://ola.hallengren.com/ amazing backup and maintenance scripts
http://whoisactive.com/ – Brilliant activity monitoring script which I use all the time.
https://dbatools.io/ – PowerShell module for SQL DBAs – This is amazing and has completely changed the way I work.
https://www.sqlskills.com/ – training, blog. Well worth reading Paul Randall’s paper on Wait statistics.
https://sqlsaturday.com/ – Free events for SQL’ers.
https://www.mssqltips.com/ – great tips website
https://sqlbits.com/ – Biggest SQL Server conference in Europe.
https://www.pass.org/ – Large SQL community with events, tutorials and more.
https://www.sqlshack.com/ – training, blog, troubleshooting, interview questions.