Live operation

Hello everyone.

I would like to work with a cd live version of trisquel.
I keep being newbie as trisquel.s user.

There are several issues for me to use it in that way:

1.- Updates ... no permanent updates if you are running a cd-live
2.- This is the most important.... I would like to work with my data (im only want to keep: bookmarks, history of brownser, and emails offline) with a usb card. I would like to keek a permanent backup of my date usb key in another media like dvd-r or similar as well.

Do you know some easy guide for do these things?.
Thank you very much.

PD . Main issue for me its to keep a hd on the computer.