Below is a link to Adobe's support article on how to electronically sign PDF's from within Adobe Reader. 

Adobe Reader is installed by default on all district computers. If you cannot locate this program click on the Start button in the bottom left-hand corner and type "Adobe Reader". You should see the program listed as an available option.

Note: If you are unable to find the e-sign option on the top bar of a document there is also a pop-out window on the right-hand side (see below).