LGBTData.com
Curated by Dr. Randall Sell at the Drexel University School of Public Health, this site includes information on which government datasets include questions about sexual orientation, and advice on sampling and measure instruments when studying sexual orientation or LGBT populations.
Data Resources from the Center of Population Research in LGBT Health
This site contains datasets and publications--some of the datasets are free to use, and some are restricted to institutions with ICPSR subscriptions (MSU has a subscription).
EU Agency for Fundamental Rights Survey Data Explorer: LGBT Survey 2012
This survey collects information on violence experienced by LGBT individuals in the countries of the EU, and also has about LGBT experiences with healthcare.