I don't know if anybody will actually want to download it, so this is something of an experiment. :-) Still, I've seen some people distributing their fic this way, so perhaps there is a demand for it.
Magic in the Buffyverse PDF - right-click and 'Save As'
It took a while longer to create than I anticipated, because I managed to crash Word, the file was so big. ;-) So instead I had to break out the InDesign and paste the text and images into it in proper approved DTP stylee.
Also, when I wrote the original essay, I tried to include screencaps of as many different spellcasters as possible, rather than just having picture after picture of Willow. So there are pictures of Buffy, Xander, Dawn, Giles, Spike and Amy casting spells as well. Of course, as frenchani pointed out, I did manage to leave out someone important in spellcasting terms to the show. So, for her, here's Ethan Rayne doing some acid...