There is a wealth of statistical material available online, much of it produced by state and federal agencies of various kinds.
An excellent resource is Research Data Services, found on the Columbia University Libraries website. Their Research Guides include data resources for Election data, NYC data, Geospatial Data and more.
Each section includes extensive listings of citations and links for major resources in the Columbia University Libraries and accessible on the Web.
The Digital Futures Institute (DFI) at Teachers College periodically hosts workshops on statistical data analysis tools and programs. Check their calendar for more information.
For education statistics, particularly ones specific to education in the United States, the website of the National Center for Education Statistics (NCES), produced by the U.S. Department of Education's Institute of Education Statistics (IES), is a key source of information. The NCES produces several annual reports that are considered essential education resources, including the Digest of Education Statistics, the Condition of Education, and Projections of Education Statistics. The NCES site also provides access to Surveys and Programs, a School, College, and Library Search, and other resources and search capabilities.
For international education statistics, check OECD Data from the Organisation for Economic Co-operation and Development (OECD).