Here are a few websites that I've found invaluable through the years.

www.prospects.ac.uk

www.lcan.org.uk

www.lgcareers.com

www.ilex.org.uk

www.solicitors-online.com

www.pupillages.com

www.lawsociety.org.uk

www.barcouncil.org.uk

www.thelawyer.com