Anyone performing construction work in California on jobs that totals $500 or more in labor and materials must be licensed by the CSLB.  Beware unlicensed contractors are part of a multi billion dollar underground economy that does not pay taxes, insurance or follow safety laws.

Your electrician should be bonded and insured and if they have employees they must carry worker's compensation insurance.  You may ask to see proof of liability coverage, business licenses, tax ID and bonding.  You can view their history and information at www.cslb.ca.gov entering the contractor's license number.  Remember that the higher the number the newer the license.

Your contractor should provide you an estimate or bid in writing.  Ask the contractor if it can be emailed to you.  The esimate should be free.

Ask the contractor if they will obtain the necessary building permits for you from your city building department and what the charges will be.

The contractor should disclose in advance and in writing of their work is guaranteed.  Typically any changes to the scope of the project should be agreed to in writing by the customer and contractor.  This is also known as a "change order".