Puppy is not developed as a multi-user distribution. In contrast to other distributions each user has full access to all files, programs and personal data. Nevertheless there are some options for multiusers.
If several persons work with Puppy, you can assign a pup_save.2fs-file to each person. In this way each person can configure Puppy individually and store his personal file in his own pup_save.2fs-file.
All pup_save.2fs-files must be in the same directory and must begin with "pup_save". For example, if there are two users Julia and Alexander you make a copy of the original pup_save.2fs-file first. Then you rename the original file as pup_save_Julia.2fs and the copied file as pup_save_Alexander.2fs. When starting Puppy askes which pup_save.2fs-file to use.
As described in chapter 4.4, each user can use its own Puppy CD/DVD with his programs and his personal files. To do so use the boot option multi-session. Even though multi-session is really interesting I am hesitant to save on the same CD-/DVD-data medium again and again. I would always be afraid of losing my files.