The hardest part, in CA, is that you can't apply until you're ready for the pre-inspection. That means you have to invest tons of money to completely build an safe hot facility for housing and preventing escapes of venemous reptiles. You also have to be zoned 'commercial/agricultural' to keep venemous reptiles since you can't simply keep them in any neighborhood.
Once your facility is constructed, furnished, and up to code, you can apply for the permit (paying a fee of course) and wait for F&W to contact you about inspecting your facility. Once they've completed the inspection (and you have no discrepencies), you pay another fee for the license that's good for one year. If you have any discrepencies, F&W can require a reinspect (at additional cost to you) until you pass with no discrepencies. During the licensed year, you can be inspected at anytime, both announced and unannounced, so keep ahead of the regs.
In case you haven't deduced it yet, there are no hobbyist permits granted in CA. All approved hot rooms are expected to be used for the study of venemous herps (institution-approved) or the collection of venom for serum research/production.