okay, leme take the plunge...
first off, if you mod your planes, you cant fly online. you ll get a error message.

Then... dont fly the planes that came with the game... my advice.
get your browser to www.avhistory.org and start flying the real deal, with better damage profiles and plane handling.

The spit you are actually flying is a little bit too manoevrable and weak. One Flakburst and you re dead meat.

hey shure no problem.
so lets start: in this game, like FS 2004 and 2002 and others, you can add Stuff in.
Planes. Scenery.
replacements for clouds. new stars, etcetcetc.

theres even tanks and cars that you can drive. no sh!t

fisrt off, you will need to set your ingame values straight. dont use the easy modes for Flight behaviour.
turn down your weapons strength and so forrth.
set AI level to high, to make them harder ot beat.

Then your tools: theres a hewp of things you can have, as i said above. depends what you are interested in.
Planes: might want to download new planes to use and abuse them.
Important here is to read the readme, and asq questions if anything isnt 110% clear as sunlight.

So download a plane and install it carefully.
dont freak if you get a Crash of Cfs3, it happens to all of us at one point, its in 99% the humans that screw up.
tell me something you d like to have cause you ve seen it, and we ll set you up, if you have problems.