For a good couple of years after I first started working with PowerShell, I had a couple of quick reference guides and this cheat sheet pinned to the wall next to my desk and it saved me checking the online help numerous times. Having them practically in my sight line all the time definitely made me more productive.
Now that PowerShell covers so many areas, we need more cheat sheets. Thankfully the PowerShell community is very obliging, so there are now a bunch of them covering different products. I'll update this post as I find more - if you find any I've missed, please let me know in the comments.
- PowerShell Quick Reference
- Windows PowerShell Refcard
- PowerShell 2 for Dummies Cheat Sheet
- Active Directory PowerShell Quick Reference
- PowerShell for Exchange 2010 Cheat Sheet
- Exchange Shell Quick Reference (Exchange 2007)
- SharePoint 2010 PowerShell Cheat Sheet
- Lync Server 2010 PowerShell Cheat Sheet
- vSphere PowerCLI Quick Reference
- vSphere PowerCLI 5.0 Poster