There are lots of resources available to help you develop your searching skills. Here are a selection of books, websites and articles that you may find helpful.
Books
De Brun, C., and Pearce-Smith, N. (2009) Searching skills toolkit: finding the evidence. Chichester, Wiley-Blackwell, 978-1-4051-7888-4 McKibbon A,
Eady A, Marks S. PDQ evidence-based principles and practice . Hamilton, Canada: BC Decker Inc., 1999.
Articles
Bidwell SR. Finding the evidence: resources and skills for locating information on clinical effectiveness. Singapore Med J. 2004 Dec;45(12):567-72, quiz 573. http://www.sma.org.sg/smj/4512/4512ebm1.pdf
Haynes RB. Of studies, summaries, synopses, and systems: the "4S" evolution of services for finding current best evidence. Evid Based Nurs. 2005 Jan;8(1):4-6.
Haynes B. Of studies, syntheses, synopses, summaries, and systems: the "5S" evolution of information services for evidence-based healthcare decisions.Evid Based Nurs. 2007 Jan;10(1):6-7.
Howes F. et al. Evidence-based public health: The importance of finding 'difficult to locate' public health and health promotion intervention studies for systematic reviews. J Public Health (Oxf). 2004
Mar;26(1):101-4. http://jpubhealth.oxfordjournals.org/cgi/reprint/26/1/101
Richardson WS et al. The well-built clinical question: a key to evidence based decisions. ACP Journal Club 1995 Nov/Dec, A12-13. http://www.mclibrary.duke.edu/subject/ebm/ebm/richardson.pdf
Schardt C et al. Utilization of the PICO framework to improve searching PubMed for clinical questions. BMC Med Inform Decis Mak. 2007 Jun 15;7:16. http://www.biomedcentral.com/1472-6947/7/16
Web resources
Centre for Evidence Based Medicine, Oxford. EBM Tools; Finding the evidence http://www.cebm.net/index.aspx?o=1038
Centre for Health Evidence 2007. Users' Guides to Evidence-Based Practice. http://www.cche.net/usersguides/main.asp
National Library of Medicine (USA). PubMed tutorials http://www.nlm.nih.gov/bsd/disted/pubmed.html
The Cochrane Library on Wiley InterScience: Quick Reference Guide. Feb 2009. http://www3.interscience.wiley.com/homepages/106568753/QuickRef.pdf
NHS Evidence http://www.evidence.nhs.uk/
NHS Evidence National Library for Public Health (PHCN). http://www.library.nhs.uk/publichealth/
Public Health Commissioning Network. http://www.phcn.nhs.uk/