Short version:
Bringing guns you already own into the state is cake, just take them to the police station to register them within 72 hrs. of arriving. But be sure to check the black-list before you bring them. (NO class-3, NO "Assault Pistols", etc. At least it's not as bad as CA) You may want to call ahead for an appointment... The lines get pretty long, and the hours are a little sporadic.
Buying guns once you're here sucks. Need a "Permit to Aquire". For long guns, it's not so bad... once a year renewal, as many purchases as you want... but for handguns, it's one permit for EACH purchase... with the requisite bureaucratic time-waste, and several trips back and forth between your FFL and the HPD.
CCW doesn't exist. We're a "May issue" state... and the PD brass are all anti-gunners, most of the LEO's I've met, not so much... but they've got their orders.
Link to the statues:
http://www.honolulupd.org/informatio...p?page=gunmain