List of Documentation to Save/Print

I'm a probationary fed who has been on for about 10 months. Can anyone help me compile a list (or point me to a list that has already been compiled) of files/documentation that I should be saving/printing? So far, I've saved my SF-50, performance review, and 6 months of paychecks. I've heard I should be going into my eOPF and downloading that. I'm about to do that now. What else?