Here's some ideas!!

Officers and Soldiers pre 1921
Because of bombing in 1940 only about 25% to 30% of soldiers' records from the period 1914-1920 have survived. The remainder can be found at The National Archives:
The National Archives,
Ruskin Avenue,
Kew,
Richmond,
Surrey TW9 4DU.
http://www.nationalarchives.gov.uk/The National Archives, which covers England, Wales and the United Kingdom, was formed in April 2003 by bringing together the Public Record Office and the Historical Manuscripts Commission. It is responsible for looking after the records of central government, including the War Office files and records amongst which are to be found surviving unit war diaries and army service records.
TNA does not undertake research for enquirers. Its public opening hours are as follows:
Monday 9.00-17.00
Tuesday 10.00-19.00
Wednesday 9.00-17.00
Thursday 9.00-19.00
Friday 9.00-17.00
Saturday 9.30-17.00
Admission is by Reader's Ticket. Readers have to register in person bearing adequate proof of identity, such as a passport or UK driving licence or UK bank/credit card. If in doubt the applicant should call in advance of their visit on 020-8876 3444.
Intending Visitors are advised to check (a) the opening times prior to a visit as sections are occasionally closed for stocktaking and (b) that the documents are available for consultation, as they are sometimes withdrawn for official use.
If you are unable to undertake the research personally, or send a proxy, the National Archives should be able to provide details of professional researchers and their charges.
http://www.nationalarchives.gov.uk/familyhistory/military/army/default.htm for information on the National Archives' collections of World War I records.
For medals honours and awards -
AFPAA (JPAC)
MOD Medal Office,
Building 250,
RAF Innsworth,
Gloucester,
GL3 1HW
Enquiries about decorations for gallantry and distinguished service (except those relating to Northern Ireland) prior to 1980 should be addressed to:
The National Archives,
Ruskin Avenue,
Kew,
Richmond,
Surrey TW9 4DU.
http://www.nationalarchives.gov.uk/Awards are announced, sometimes with citations, in Supplements to the London Gazette. Copies of London Gazettes are held in the National Archives at Kew and in several of the principal reference libraries. Any public library should be able to help you find a library that holds it.