NATIONAL-BASED SITES
Royal Institute of British Architects (RIBA)
The main Institute that regulates all architects, lots of current & relevant information.
Design Council
The main organisation which promotes the purpose and importance of design. some great resources available.
ARCHITECTURE MAGAZINES
Design Week
A weekly web-magazine on all things design. Has some great current case-studies.
Dezeen
An on-line magazine in relation to current affairs in Architecture