See especially the Reports & Presentations section. Annual reports for as recently as 2014 are searchable as PDFs. Profiles and locations of the world's top 50 dumpsites are included.
This 65-page report by the International Labour Organnization contains good information on the competing definitions of e-waste, the flow and the business of e-waste, statistics on e-waste, and the interconnected labor issues. A very good and well-cited overview.
