Zip guns are considered homemade guns. Do a Google search on Zip guns to find out how.
You can find information on how to make a gun online on Youtube and also at Wikihow. You can learn to make a 22 pistol and also you can even learn how to make a machine gun.
You will have to contact your local police to find out.
You really shouldn't man...
youtube it
Three Words For Ya- Use... A... Balloon
One can find plenty of information about gun shows on websites such as "Showmasters", "Cross Roads Gun Shows", "Gun Show Trader" or "East Man Gun Show".
Library, gun shop, gun shows, the internet
Have a degree in chemistry. Do not put anything in your gun besides air-tool lubricant (for mechanical guns), or actual paintball lube.
Nope but you'd might want to check this out. It seems the NSW Police half-assed it when they tried to build a gun themselves.
Blue Book of Gun Values
Mainly from the markings on the gun by the maker.