In case you missed these elsewhere in cyberspace …
1) See this compiled list of 2013 Mayday actions: Global Reports of May Day Actions 2013
2) Joint statement by USA/Canada groups and links to Anarkismo statements: Mayday. Remembering the past, fighting for tomorrow.
Read a nice summary of Mayday’s origins in the USA from the Bristol First of May Group.
For a full history of the Haymarket Affair, the Haymarket Martyrs and the origins of May Day
watch this talk by Bristol Radical History Group from 2012 (YouTube video)
See also (from Bristol AF, 4th May 2013): Radical Block Marches in Solidarity with Bangladeshi Workers at Bristol May Day
See also (from Cyber Anarchia, Dundee, 7th May 2013): May Day: Thoughts and considerations
See also (from IFA website, 4th May 2013): May Day Resistance in İstanbul.
See also (First of May Anarchist Alliance, Detroit): Revolutionary Greetings – May Day 2013