A charitable trust or foundation is normally set up by an individual or organisation with the aim of distributing money to benefit certain sectors of society, or society as a whole. Some trusts give money for general charitable purposes, while others have stricter criteria which you will have to meet to be eligible to apply. A useful website for researching trusts is TrustFunding.org.uk, which at the time of writing (August 2010) cost £287 for 1 charity user for 12 months.
Some trusts have a definite deadline to apply for funding, while others have rolling deadlines, depending on how frequently the trustees meet. Some are happy with a general letter of application, while others have their own application forms which you have to fill out.
A general letter to a trust should include: