You could make a career out of PowerShell (just ask our frequent contributor and PowerShell expert, Don Jones). But if PowerShell's only one of a few million things you need to learn quickly, take a look at some of these most popular and recent resources.
1. Check out Don Jones on PowerShell. Don's a well-known PowerShell expert, author, and instructor, and he updates his blog several times a week with practical PowerShell tips and tricks. He recently blogged about other PowerShell resources you can use. Don also has a series of longer PowerShell articles on Windows IT Pro. Trying to tackle debugging in Windows? Don lends a hand with " Debugging in Windows PowerShell."
2. Visit John Savill's FAQ page, which includes many PowerShell tips. For a sample, see John's introduction to PowerShell cmdlets for AD.
3. Greg Shields also covers some PowerShell tips in his virtualization blog. For example, Greg shows how to use the GetCluster cmdlet in Windows PowerShell and a subsequent tweak to his tip.
4. Darren Mar-Elia talks about how you can use PowerShell to automate Group Policy management in Windows Server 2008 R2.
5. And one from the archives ... an old but good one from Robert Sheldon on accessing SQL Server from PowerShell--a two-part series.
Happy scripting! And don't forget to follow me on Twitter.