We have several users in the field with MacBooks.

Because they're not always on the network, they save files locally to their notebooks. Normally I back things up by making quick copies to other media, but with the Macs they have the option to run Time Machine (and the way OS X is designed, they're heavily encouraged to use it.)

Question; for maintaining Macs and data, how reliable and thorough is Time Machine for backup/restoration? Does it just back up the user's home directory, or can it restore the Mac if, for example, the drive fails?

And are there options for "securing" the data like corporate backup software for Windows does, to encrypt the data on the time machine drive?