well,thanks a lot :D

***
Download instructions are standard for all.

After you input the link on your browser, you can see a "DOWNLOAD" button on the screen.
It will show something like "Dallas USA" with a green download button beside it.
However i think it depends on your area though. Click on it to download.

After downloading the content ( it will only be a file),
Copy the downloaded vpk. file and paste it to

My Computer > C:/ Drive > Program Files > Steam > SteamApps > common >
l4d2 > l4d2 > addons

After pasting the downloaded content into your "addons" folder, just double click on the file
and there will be a pop-up that says that the file is successfully installed. The map is now ready to be played! (Remember this step)

However if you cannot find "Steam" in your program files, then just right click on your Steam Icon and click "Open File Location". And if you're using MAC OS, I think you have to most probably search for Steam.

Yup, and that's all for now! =D

Cheers!

There are many more maps that I have downloaded, however i'll just stick with these first. =D
If you ask me which ones are better, i couldn't answer you. They're all great maps :D
Personally if you like long and challenging gameplay, I would recommend both the Silent Hill
maps or Questionable Ethics. Other ones are just 5/5 map games, however fun and enjoyable as well.

http://www.gamemaps.com/details/2850 (Yama)
http://www.gamemaps.com/details/7592 (Silent Hill: Otherside of Life)
http://www.gamemaps.com/details/6772 (The Bloody Moors)
http://www.gamemaps.com/details/2119 (Vienna Calling 1)
http://www.gamemaps.com/details/2719 (Vienna Calling 2)
http://www.gamemaps.com/details/2390 (Heaven Can Wait II)
http://www.gamemaps.com/details/6084 (Journey To The Splash Mountain)
http://www.gamemaps.com/details/2849 (Redemption II)
http://www.gamemaps.com/details/4099 (Silent Hill)
http://www.gamemaps.com/details/2633 (Military Industrail Complex II)
http://www.gamemaps.com/details/2795 (Questionable Ethics)
http://www.gamemaps.com/details/2682 (One 4 Nine)
http://www.gamemaps.com/details/11669 (The Cure)
http://www.gamemaps.com/details/2597 (Night Terror)
http://www.gamemaps.com/details/8338 (Beldurra 2)
http://www.gamemaps.com/details/2268 (Dead Before Dawn DC)

Hi, good day to you =D

I'm just going to put some links here for l4d2 addon maps.
These links are l4d2 maps that i have downloaded and that i enjoyed.
I won't be giving game descriptions as you can look at the details after pressing on the links.

(These maps work Campaign/Realism mode, not sure if it works on Versus/Mutation /Survival, however do check the map details when you press on the link.)