You can choose how much you want to give each month (minimum £10) and the charities you want to give it to. This is a tax efficient way of giving since the donation is deducted from your pay before tax.
The payroll department send your donations to the Charities Aid Foundation who will then send you a charity chequebook and CharityCard so you can make donations to whichever charity you wish.
The University of Warwick is a charity with donations funding scholarships, pioneering research, volunteering projects and much more. You may wish to consider donating to the University via Give As You Earn.