Google: (of course). Usually I just type phrases I want to research into the Google search engine and something always comes up
Royal College of Nursing: You have to be a member to access the e-library but it is superb - with access to over a dozen nursing-related publications and over a hundred books to view online. The British Nursing Index which can be accessed through this site is another useful resource.
Nursing Times: register first for access to an archive of articles online
Nursing Standard: register first for access to an archive of articles online
Community Care: search an archive of articles online without having to register
British Medical Journal: search an archive of articles online without having to register.
Guardian Unlimited: another unexpectedly valuable resource, by the Guardian newspaper.
Care and Health: search an archive of articles online without having to register
Medscape Psychiatry: this North American site is a little parochial sometimes but it is superb for the amount and breadth of information and studies that it offers. Register for access to the site and a weekly email giving current updates.