Editing PDF Files
http://www.docu-track.com/home/prod_user/PDF-XChange_Tools/pdfx_viewer


Making How to Videos
I've used Jing videos when teachers need a quick "how to". It captures video of whatever you're doing on your computer and you can narrate as you're going. Then it's easy to send in an email.

http://www.jingproject.com/ . allows for screenshots both video and still, editing, sending these by ftp, upload to flickr, email or hard drive.