HOW TO INSTALL ADDONS

I'm trying to add my addons in wow and it's installing. i followed the instructions and nothing. Please help!!!!!!

Dude nice guide i understood the first one...had to read it a few times, ahwell it was gd stuff 5* nice one

im tryin to download auctioneer and it wont show up like map coords does, did a patch kill it?

Er i need help im playing wow on a macbook pro and when i download the addon it shows a lua file but when i copy and paste all the contents into the addon folder i cant use it how do i install addon in macbook?

this how i do it in 20 small easy steps;
1.got to wow.curse.com
2.find the addon you want
3.click download
4.click choose mirror automaticly
5.click open
6.it will download and appear in a diffrent window as a folder click extract all files
7.it will appeear in a diffrent window , so delete out of the old one
8.go to start menu on you desktop and go to "computer"for vista or "my computer"
9.go to your local disk if you did default download (normmally drive C)
10.go into that and look for program files
11. go into program files and scroll down till you find world of warcraft
12. open that and go to interface
13.then go to addons
14.and all you have todo is drag the addon that is in the diffrent window into the addons area
15.log into WoW and youll see addons click in the top right ignore out of date items
16.select the ones you want (usally all)
17.login and they'll take effect.
18.still having trouble? need a video? heres one : http://youtube.com/watch?v=HORz4U5ot98
19:copy and paste that to your adress bar on the internet(NOT WoW)
20:this is not me! i found this video! WARNING: not all addons will work it is usally the addon that doesnt work if you have some trouble.

ive downloaded multiple addons via curse and they have all went to the WoW game without having to do a thing. my problem is what file do i go to to add music to the addon "musicplayer"? i could not find an interface file in my WoW file. can anyone help me with this. its been bugging the hell out of me for the past few days. ive created a new folder with "interface" and then in that folder "addons". where can i find the addons to drop into the "addons" folder when they are allready in the game? and please keep in mind that i am compleatly computer retarded. please help

ok i have a small problem i extracted the file like i am supposed to do but i don't know witch add on file to add it two... the reason being is there two different add on file with two different locations i will post the name so you will know what they are and hopefully some one can help me .. just so you know i have update my account to the new burning Crusade... also i put my wow in program files i don't know if that matters or not...

ok the name of the two files that have add ons in them

1. blizzard Interface Data (2) sub files : 1 Add ons 2 Frame XML

2. Interface 200080222-20037 (1) sub file 1 add ons...

now i tried to add the extracted files to one or the other but i still cant seam to get it to work..
i drag and drop the now extracted file to add on and i still don't see the the box that is supposed to show up.

Please help if you can thanks

Put it in the one without the numbers, other one is an auto backup

i have tried that and i still do not see the box that is supposed to show up..

Ok so I'm a complete novice but whenever I try to download an addon it starts then gives an error message <failed to open previous instance Error 00000>
and help?