Great external PowerShell resources (in alphabetical order):

• Aaron Nelson - http://sqlvariant.com/wordpress/
• Allen White - http://sqlblog.com/blogs/allen_white/default.aspx
• Chad Miller - http://sev17.com
• Don Jones - http://www.windowsitpro.com/blogs/PowerShellwithaPurpose
• Ed Wilson - http://technet.microsoft.com/en-us/scriptcenter
• Sean McCown - http://www.midnighdba.com/DBARant