Legal Question in Intellectual Property in California

Business "ideas" per se generally don't qualify for protection under the copyright, trademark or patent laws, so the best advice is probably to choose your contractors or employees carefully. There's perhaps a possibility that your idea might rise to the level of a "trade secret" as that term is used in the law. You should probably look up the California version of the Uniform Trade Secrets Act, which is codified as Civil Code sections 3426 - 3426.11. Look in particular at subsection 3426.1(d) where "trade secret" is defined. If your idea might qualify, then have your employee(s) and/or contractor(s) sign a simple, brief statement acknowledging that you consider the information you'll be imparting to them to include trade secrets and that they promise not to misappropriate them. No guarantees, but this might be helpful.