Tip 1: To quickly find out the build level of SharePoint 2010 using Powershell, use the following commands:
$farm = Get-SPFarm
$farm.BuildVersion
Tip 2: For a list of build numbers, go to Joe's blog: http://blogs.technet.com/b/sharepointjoe/archive/2011/02/01/sp2010-sharepoint-2010-build-level-and-version-numbers.aspx
Tip 3: For the latest patches, go to this site: http://technet.microsoft.com/en-us/sharepoint/ff800847.aspx
