Thank you guys for the help. It looks like I have some reading to do so I can learn how to build a mod.
Okay, I have a start on my test mod to learn. However, I am stuck. I need to know how the find the games Art files, such as UnitArtInfos and UnitMemberArtInfos. I need them as a reference to add my airplane. BTW, I did download firefox and SQlite like the tutorial said (at this point I am not sure what I need the database for yet but oh well). I just need the rest of the game files as a reference for the ArtDefines xml code.
One more thing, I am not sure where to put the unit folder (I am using danrells SPAD biplane as the base early aircraft) that has the animation files and so forth. Sorry for being a noob to all this, but I'll learn. Thanks for the help.