After you have written up the purchase agreement and all terms have been accepted and escrow opened, the next step and one of the most important parts of the purchase is to make arrangements to have the property inspected.  This is usually part of the sales agreement and in California you have 17 days, unless waved or extended, to make your inspections and do your due diligence.

Most buyers hire a local certified inspector, who inspects the property and gives a report back.  This report usually covers such areas as: electrical, plumbing, built-in appliances, safety hazards and a visual of structural integrity.

Most important to remember, this is not a sellers repair list or a deal breaker, unless there are major issues with the property.  Most sellers will work with the buyer to correct some, all or none of these request.

Land should also have due diligence, done by the buyer, to address such things as boundaries, easements, soil testing for percolation etc.

It is important to know as much about the property you're buying as possible so there won't be any surprises after escrow has closed. 

Ask your Realtor, you're working with, for a list of local qualified inspectors you can call to interview and get cost estimates for their report... As any business they have different pricing and qualifications.  The industry is not regulated by law, at least not in California, so make your selection based on factors such as,  years of experience, certification or schooling and someone you can work with.