Instead of making photocopies of handouts for students, you can scan files via a copy machine and distribute the electronic version to students (via Moodle, Edmodo, Q:Drive).  This is a great way to distribute articles, slideshows, or any other handout that students will read and take notes on.  Here are some tips that will help you with the process
 
You can easily record and insert an audio file of your voice on a PDF.  This can be used to provide instructions for an activity or provide students with feedback on assignments.  The next time you open a PDF, any PDF, try the following. . .  

Go to Tools > Comment & Markup > Record Audio Comment  and a little recording icon will appear > Click somewhere on the page to place the file > Click the red dot to record >  Start talking, right at your laptop (there is a mic by the web cam) > Click OK when finished recording > OK