I've been living in Belize for long enough to become a national but have no idea what the laws are on
1. Owning a gun
2. Carrying a concealed gun
3. Importing a gun
4. Purchasing a gun
Does anyone know where I can find the rules about civilian firearms?

Sit down at the police station and be patient and polite, they will explain the rules to You. Permits come out of Belmopan and ammunition is also with a permit. You can shop for the weapon in Belize city, pick it out and then apply for that specific firearm while the merchant holds it.
Expect an interview and a document stating you have no police record, ironically the document is called 'Police Record' you can apply for a police record at the police station with $12.bz and two photographs.There is a yearly fee as well.
Don't know anything about importing a weapon...bet it's much harder.
http://icbl.bz/lob/Chapter%20143S.pdf

Thanks Elbert! It's been some time but I think the police record takes week/months to get from the island and it can be got in a day by going to the station in Belmopan. Any idea of who sells in the city or where I can find the info for importing? Currently I'm in the states, it would be great to bring down the make and model of my choice.

Elbert is correct in the procedure for getting a permit, the yearly fee is $75.00 and is due on your birthday. All handgun permits are for concealed guns, you cannot walk around with the gun visible, that will get you arrested. You have to show the need for a firearm, and be prepared for a very long wait. It took almost 2 years before they granted mine, but there was a moratorium on firearms license during that time. Applying and filing all the correct papers does not guarantee you will be granted a license.

I would like to see a gun club in San Pedro, anyone interested in starting one??

Interesting, I wonder if self preservation is considered a need. Responsible owenership, use, and training would be some good requirements. A gun club could certainly help instill some of that.

Do you apply at the station in Belmopan?

Check this page.
http://www.police.gov.bz/index.php?option=com_ionfiles&Itemid=170

to import a gun: when you buy the gun and authorized dealer sends it to the airline. When it gets to Belize it goes straight to customs. Then, you take your import permit to customs and then they send the gun and the permit to Belmopan. Then you take your gun permit to Belmopan and pick up your gun.

Gun permit fees are 500.00 bzd per year for Residents and 75.00 for CITIZENS

PS: the duty on the gun is 100% of it's value.

108% duty and you can only have certain types of handguns. 22, 38 and 9mm only. Its about the same price to buy one here. victor Bryant in Bz City is the place to go. You can also buy ammo there or at Bennie's. 100 rounds is max you can legally have