Instructions:Was just handed a book of vouchers at Liverpool Street Station this morning. However, you can also apply for a month's booklet of vouchers at http://www.guardianvouchers.co.uk.
As far as I can tell, its:
40p off for Mondays to Fridays
80p off Saturdays
£1 off Sundays (for The Observer)
Cracking deal if you're a regular reader of The Guardian.