How do I add units?

[FNK_Drake]

Ive been Playing Civ4, and Civ games in general for a long time. But since Civ4 is so moddable, and theres tons of unit models availible I want to add a few to a Mod I have installed (epic Mod 1.02)

I have some basic understanding of the .XML Code, but not alot.

First of all, I feel like playing a Naval game, so I figured id play a map with tons of islands. but WW2 era naval combat is a little un-realistic. Aircraft Carriers arent nearly as useful as they should be. they only carry fighters which are useless against other ships. woudl there be a way to add Dive bombers for use against ships and also land targets and actually have the AI use them?

I know theres atleast one country with a UU availible.. and i probably coudl use the fighter as a generic version..

what about torpedo bombers?.. i havent found any models tho.

Could I create a new class of unit, and have the carriers be abel to carry them?.. or coudl i classify them as Fighters?

How do I add UUs for Nations (what part of .XML code do i need to change? Example: Adding the CV Zuikaku for Japans UU replacing Carrier) (and how do I use the unit models ive downloaded?)

Can you add UUs that dont replace the original units?

Also, before I start modding this Mod, is there any other Mods anyone can recommend for adding tons of UUs for different nations??.. im especially interested in the WW2 era.

that all I can think of for now. Thanks for any help