The British Library
The BL's Family History Search is an index of many European baptisms, marriages, and burials in India.
http://www.bl.uk/catalogues/iofhs.shtml

Indian Cemeteries
Photographs and transcriptions from Indian and Pakistani Cemeteries.
http://www.indian-cemeteries.org

The Families in British India Society
FIBIS have a searchable database of East India Company and India Office biographical data and an online encyclopaedia (the FIBIWiki) relating to the British in India.
http://www.fibis.org

Commonwealth War Graves Commission
Records of 1.7 million Commonwealth soldiers who died in the First and Second World Wars.
http://www.cwgc.org

Kabristan Archives
Inscriptions from Indian and Sri Lankan graveyards.
http://kabristan.org.uk/

Koi-hai Directory
A lively newsletter for mainly tea people and planters who served in north-east India and Assam, and they do carry articles about graves on tea estates.
http://www.koi-hai.com

The National Army Museum
Britain’s conflicts from Hastings to Helmand.
www.national-army-museum.ac.uk

The National Archives
1,000 years of history.
www.nationalarchives.gov.uk

The British in India Museum
www.britishinindiamuseum.co.uk

"War Memorials Trust
A Charity working to protect and conserve war memorials in the UK.
www.warmemorials.org.uk