Basically, all from Ask Ubuntu at the bottom of this page. I found more information there than on the mint forum site. While these are all for Ubuntu systems they should work on your Mint11.
(Side bar mint12 seems to have an encrypt bug- to be patched at next release).
There are other answers on this and other pages + the 'Related' on the right hand side.
What it does:
The home folder is where all of your files and settings when you choose this option your home folder is encrypted. This prevents anyone who is not logged in as you from being able to access your home folder.
From the Ubuntu developer himself:
- Not sure, but you should be able to encrypt as above per user.
Type of encryption or type in terminal:
" ~ $ man encrypt "