General Sites

The Commission department devoted to regional policy has an extensive website that provides masses of data and several highly readable explanations of EU policy in the area. See
europa.eu.int/comm

A paper on regional policy and EU enlargement, 'EU Regional and Cohesion Policy and Economic Integration of the Accession Countries':
ideas.repec.org/p/wpa/wuwpur/0204002.html

A whole site on EU structural spending in Ireland (one of the biggest recipients per capita until recently):
www.eustructuralfunds.ie

A UK government description of the Funds, how to get them, and examples of actual projects
http://www.dti.gov.uk/regional/european-structural-funds/index.html