Make Your References Work for You 

Make sure you have references.  Sounds simple.  You'd be surprised how many people cannot come up with a name or two when asked.  It's hard for me to understand how you can work at a company for X amount of years and not be able to produce the name of a former supervisor, colleague, HR rep, or customer that can vouch for you as a person and your experience.  The inability to produce references can serve as a major red flag!

Keep your references current.  Don't just dust off the old list that you used during your last job search.  Make sure the contact information listed is all accurate.  References do no good if I am unable to reach the person. 

Call your references ahead of time.  Give them a heads up.  Let them know that you are currently on the job search and to expect a call from prospective employers or others assisting in the job search.  Make sure they are still ok with being one of your references.  Who knows, if you've worked with them in the past, it is possible once they find out that you are looking for work, they may have something at their company you can apply for. 

Please understand the importance of having solid references.  As much as good references can work for you and potentially separate you from the competition, bad references or no references can adversely affect you and could potentially be the reason an employer selects another candidate for a job that was meant for you.