I'm looking for a sort-of beginners guide to administering Vsphere / ESXi - perhaps something like VMware for not-so-Dummies...

 I have used the previous VMWare Server / Workstation products, got to know them reasonably well, but making the jump to ESXi has left a few holes in my knowledge. 

Have migrated all our test enviroments to ESXi, that was easy.

At the moment, have the generic root account, but anyone that logs onto that root account can see and mess around with all the inventoried devices. So I have setup a user account. Damned if I can now log into that account.
Also, would like to know how to lock down template machines so they can't be erased, or even how to create template machines - all I have setup is a seperate datastore with which I call template VM's - they may not be true templates in the VMWare sense.

Nothing too complex - these VM's are not mission critical - mainly used for training and testing.