Man, were to start...I'm a bassist like you...and would like to someday build me a jazz or precision bass copy with my personal touches...
You will never stop finding resources...if you look for them. There are TONS of articles, videos, "how to's" and books out there.
I think iT Is best if you get some kind of book...or better...books about bass lutherie.
I would start with something VERY basic...super simple construction. Kind of like a scrapwood build. Pine or something like that. No finish, super simple electronics...maybe try building around an existing neck? But thats just me. I'm no builder myself. Good luck!