Very Brief Introduction to Open Access. (1 page; available in English and 20 other languages.)
http://legacy.earlham.edu/~peters/fos/brief.htm

How To Make Your Own Work Open Access. (4 pages; available in English, Greek, and Spanish.)
http://bit.ly/how-oa

Open Access: Six Myth To Put To Rest. (7 pages; from The Guardian, October 21, 2013.)
http://goo.gl/fzzdB6

Open Access Overview. (10 pages; available in English and 10 other languages.)
http://bit.ly/oa-overview

Good Practices For University Open-Access Policies. (87 pages; with +Stuart Shieber.)
http://bit.ly/goodoa 

Open Access. (242 pages with an extra 25+ pages of updates and supplements; from MIT Press, 2012; available in English and Polish, partially in Greek, with 10 other translations in progress.)
http://bit.ly/oa-book 

Other Peter Suber's writings on OA.
http://bit.ly/suber-oa-writings