Any gun store oughta have your Arizona hunting regs.
By and large, a grownup pigalina will run about 40 pounds or so on the hoof. A .357 Mag pistol is plenty good.
The almost-mature but not totally grownup are much better eating. If you spot a group of them, and ease up to ten or fifteen yards (simple, if you work toward them with the wind blowing from them to you, or across your path) pick out one which is maybe 2" less height at the shoulder.
Aim for the eye or right below the ear.
There are a couple of scent glands on the back, just in front of the rump. Unless you want the hide for taxidermy, cut the skin out around those glands so you don't musk up the meat.
There is no difference between gutting out a javelina than a deer, except the hide is tougher. If you're halfway careful, you won't even get blood on your hands--but they'll be a bit greasy!
Think, "Sharp knife!"
The hams will barbecue nicely at around 250-300 degrees, roughly, in an hour or so. The little backstraps make quick-cooking "num-nums" to nibble while you cook.
If you're not interested in having the head mounted, you can just boil the skull and then set it on an antbed and let them do the rest of the work. Makes an interesting souvenir.
Hope this helps,
Art