This is an excellent resource to use for advancing your skills with advanced administration for SQL servers, regardless of the number of servers you are administering. Joseph Houghes

An effective DBA is an efficient DBA. And if you work with SQL Server, dbatools is a lifesaver. With over 500 commands, this free and open source PowerShell module has the horsepower to automate just about every task you can imagine—and then some! Written by dbatools creatorand dbatools advocateteaches you techniques that will make you more effective—and efficient—than you ever thought possible.