Gasoline is a very powerful flammable liquid we all take for granted. As a firefighter and employed in the insurance industry, I can tell you a few gallons of the stuff will give you a lot of heat in a very short period of time and can do a huge amount of damage. The best container to store gasoline in is a UL Listed or FM Approved METAL safety can. They come in ½ gallon to 5 gallon size and cost from $20-$50, a very cheap insurance policy. The spout should have a screen inside of the can to prevent the vapors from igniting and it should have a self closing lid. The lid does two things, it prevents spills if the can is tipped over and more importantly, it will relieve pressure should it be exposed to a fire. The pressure build up in the can will cause the top to lift, the screen will prevent the escaping liquid from igniting the liquid inside of the can and lighting it off.
If you have a 55 gallon drum of gasoline you should store it in the upright position and pump the liquid from the drum with a UL or FM drum pump for flammable liquid. It is good practice to have a pressure relief valve in the bung you are not using to relief the pressure if the drum is exposed to a fire. The drum should be grounded, a 10-12 gauge wire connected to a 6-8 foot ½ inch copper rod into the ground. A bonding wire, a wire with two alligator clamps on either end, should be used when dispensing. One is connected to the 55 gallon drum and the other onto the vehicle or safety can you are dispensing into. The gas pump nozzle you pump gas with at a gas station has a similar set up, except you can not see it as it is covered by rubber hose. The purpose of the bonding wire is to carry the static electricity away to prevent it from igniting the gasoline. The best place to store gasoline is away from important buildings ( such as the building you have your tractor in, or your house) and in the shade.
Hope this helps, and oh yea be careful!
Regards
Tom
PS
Now for the legal stuff…
This information is based on NFPA 30, 2000 edition, Flammable and Combustible Liquids Code and is my interpretation of the code. If you have any questions please contact your local fire inspector of fire protection professional or NFPA.