89 si Questions... I know nothing about this.. please help

Hey... My freind told me this would be the best way to find out answers to questions..
I just got a 89 si prelude and i don't know anything about it... i'm use to chevy s-10's and i know just about anything and everything about stereo systems but i don't know jack about this car..honestly..
IF any of you'll could give me any and all your knowelde on this kinda car i'd really like to know any thing i can..

I'm told it has a dual over head cam engine..whatever that means and that it might be a JDM? what do these mean?
I would also like to do so customizing on this car..mods.. but am having a hard time finding parts and not only that but i don't know what all i can do with it.... please tell me anything you can.. or e-mail me with links to places for info on this can .. ultrafast69@hotmail.com or if you have messenger add me and help me.. please..

-what engine mods can i do with it?
-what's the biggest set of nice wheels and tires can i put on it?
-i've head something about switching heads? what does this mean and what kind?
-how hard would it be to do a converstion from auto to manual?
-it's a 3rd generation type right? and does that mean any part from another year of that gen type will fit mine.. ? 87-91...right?
-what does "SI" mean
-cold air intake..i've hard about them but what are they and what do they do?
-wing? do i put one on it>? does it help or is it for looks>?
-muffler/exhuast? i don't want it to sound like ass...like a soda can welded on their.. so what should i do? my buddy told me to say that i don't want it to sound like a ricer? whatever that is..

I own an 88 si and can help you with all of your questions. You can email me at sarah.harms1@mchsi.com . I have added you to my buddy list so you can reach me there. i have found pretty much everything made for our 3rd gens. Hit me up
http://files.automotiveforums.com/gallery/watermark.php?file=/503/95396down_low.JPG