Transcripts:
PTCAS doesn't accept them from students, it has to come from the school you attended. Don't forget to supply the form PTCAS requires to be included for your transcripts also.
LORs:
They can be sent by your recommenders directly (electronically or paper). But, you can send it in yourself as well. Because when I was getting all my documents together, PTCAS hadn't opened their applications yet. I had one paper recommendations before July, when PTCAS is not available, and mailed it in myself when it became available.
Observation hours:
I sent them in myself. The facilities that I observed/volunteered had their own documentation and PTCAS allows you to send that in as verification instead of having to get it verified again (it's in the instructions)