Every Authority Having Jurisdiction (AHJ) is different. Where I live (a small town in South Florida), the inspectors and building official have set "office hours" when you can find them at their desks rather than out inspecting permits. Call and ask about that first.
In my experience, the building department will
not take a paying customer away from an electrical contractor by drawing out a diagram and telling you all the parts you need to go buy to wire something up yourself. You need to be familiar with the NEC, just as an electrical contractor would be.
When I wanted to install a grid-tie solar setup, I stopped by the office during "office hours" and asked some simple questions initially: If I want to do XYZ project, what documents do I need to apply for a permit? I asked these questions of one of the inspectors, since I know they are the ones who actually utilize the documents every day to do their job. The secretary is helpful for general questions, but as a DIY guy, I like to hear from the inspector what permit package documents they commonly have in their hands on a jobsite to do their job.
They responded that I needed to utilize a "state certified" system, and they would need a diagram showing all the wiring involved, with all the electrical junction boxes, panels, breaker sizes, conduit sizes, and wire sizes labeled. They also said I would need a signed/sealed structural engineering plan showing the system won't blow off the roof in the next hurricane. Perfect, that was the "basic outline" I needed to go do my homework.
I went home and did my homework. I had never heard that PV systems in Florida had their own "state certification". So, I google'd that and learned what that meant. I designed my own system, applied for and obtained a state certification for it. In doing so, I got to read quite a bit of the NEC.
Since nearly a year passed between my initial inquiry and when I thought I had all the documents I needed to obtain a permit, I went in during "office hours" and had the electrical inspector quickly glance over what I had. Not specifically checking it to see whether it was "all according to the NEC", but simply a 30 second glance at it to see whether it was similar to other documents provided by actual electrical contractors for permit documents. I also verified that no additional documentation would be necessary, since ordinances and permitting rules change over time, and a year had passed since I originally asked what I needed.
When I was confident I had everything I needed in hand, I took three steps to the right, filled out a building permit for electrical work, pulled out the checkbook and wrote them a check to have the building official perform a real "plan review". A week later, I got a call indicating my plan review was complete and I was cleared to write another check and pull my permit. When I picked up my permit, I specifically asked the inspector what stages of the project they wanted to inspect. When each in-progress inspection was complete, I again verified what stage of in-progress they wanted to inspect next.
The day of my final inspections for my grid-tie solar system, the structural and electrical inspectors both asked me if I could please teach the local solar installers how to install a system as neatly and following the intent of the NEC as my PV system was done. As a homeowner, I try do things right "the first time" with quality materials. I've failed electrical inspections on projects, simple projects! Failing an inspection costs me several hours where I could be at my day job earning money, rather than waiting at the house from 10AM-Noon on a Tuesday. I've learned, when I have questions, it pays for me to stop, pull out my NEC book and read it, and if I have any doubt stop by the building department or call during office hours to verify my understanding meets their interpretation and expectations.
The structural PE I use spells out in his sketches the dimension of every bolt, nail, screw, the part number of every simpson-strongtie bracket, along with the type of wood and the dimensional size of every critical piece of lumber used... Leave no questions for the inspector, or the laborer swinging the hammer. I draw my electrical project diagrams to a similar standard, clearly labeling everything. The state of Florida EE who reviewed my PV system design drawings for NEC compliance to get my state certification # indicated my drawings were some of the most complete and thorough he had ever seen.
