If you are doing Windows administration, this is for you.

Fantastic introduction to Powershell, from Microsoft itself. Great tone, very practical examples and good pacing.

Hotkeys you can use from a PowerShell console. More than just arrow keys, this is useful.

A great place to start - will lead you to results quickly without distracting you with parts of PowerShell you don't need right now.

From ss64.com
A nice online companion to the built-in PowerShell help.