APA Style quick guide...

…free online, is now available from the APA: http://www.apastyle.org/learn/quick-guide-on-references.aspx. It isn't a complete guide (they expect you to purchase (or borrow from the library!) the official Publication Manual for that), but it does nicely supplement some of the other great online guides. It also features recommendations for a few reference types which were not included in the official Publication Manual e.g. how to reference Facebook and Twitter.