Well to test the water in the gas tank theory - fill up and use a bottle of HEET.
To check the IAC (iv heard many things to test this) Boil it if it doesn't whistle within 20 seconds then get a new one. put it in water if it doesn't float buy a new one or you can just buy a new one - RockAuto Parts Catalog
and to test the fuel pump you could buy a pressure gauge thing...
But wait till Bert or someone with a bit more experience to make sure what im telling you is correct.