Coming from SPC a couple of weeks ago, during the keynote there was a demo on some great Visio Diagrams. It was created using the following:
http://visiospfarmaddin.codeplex.com/
Expect a post here in the next week or so on how to configure it.
Another great tool I came across is targeted to those who are becoming familiar with PowerShell for SharePoint, and also if you want to use PowerShell with SharePoint Online. It is a Command Builder, you pick the verbs and nouns as you would regularly do with PowerShell and see the combination of parameters and information for that given command.
Give a try here: http://www.microsoft.com/resources/TechNet/en-us/Office/media/WindowsPowerShell/WindowsPowerShellCommandBuilder.html
More info on it: http://technet.microsoft.com/en-us/sharepoint/ff603532