How does one get started providing Broker Price Opinions?

[David Tipton]

My fiance has her broker's license here in California.  We heard that BPOs are a good way to earn some income while refining one's ability to value property.  

How would she get started?  Are there any educational requirements?  Is it as simple as contacting lenders and asking to be put on a list?  Any advice is appreciated.  Thank you.