What we want
1. Life before WW1:
- Date and place of birth, parents
- If married, date and name of spouse, and any children.
- Occupation and address.
- Date joined, number, rank, Regiment or Corps.
- Where he went, what battles he took part in.
- Date of death, where and how.
- Where buried and/or remembed.
How to find it
Find him in the 1911 census:
Use the same sources to search in 1901 census.
Use age and place of birth to find birth and marriage dates: http://www.freebmd.org.uk/
Search local directories or newspapers (in Rugby Library)
Most of the men on our list have the basic info, which has come from http://www.cwgc.org/
Look at the details of the cemetery/memorial, it might give you information about how and where he died. Look at the associated documents - you might find wording on a headstone and the name and address of a relative. A soldier may have been reburied and information given of how he was identified.
Medal Roll Index Lists: http://search.ancestry.co.uk/search/db.aspx?dbid=1262
Also on Ancestry are: British Army WWI Service Records, 1914-1920, British Army WWI Pension Records 1914-1920 and much more. Start at "Military Records". Find your man and it will recommend other records. UK, Soldiers Died in the Great War, 1914-1919 is good as it shows place of birth and of enlistment (hopefully Rugby). A recent addition is UK, Army Registers of Soldiers' Effects, 1901-1929 which give details of next of kin.
The medal index cards can also be downloaded from TNA (£3.36) http://www.nationalarchives.gov.uk/records/medals.htm
There is a lot more at TNA. Check the Research Guides on specific subjects. Links to soldiers, sailors and airmen can be found here http://www.nationalarchives.gov.uk/records/looking-for-person/
If you know the Regiment, you can download the War Diaries to find out what was happening http://www.nationalarchives.gov.uk/records/war-diaries-ww1.htm
WW1 Soldiers Wills can be found at https://www.gov.uk/probate-search although they cost £6 to download. National Probate Calendar can be useful for finding relatives.
Other useful sites:
http://www.1914-1918.net/ The Long Long Trail: The British Army in the First World War
http://www.roll-of-honour.com/ A collection of databases
www.thegazette.co.uk Official notices of military awards
http://www.iwm.org.uk/ Imperial War Museum
http://www.ffhs.org.uk/ww1/intro.php An introduction to WW1 and lots of links.