Ok, first of all, "idle in mirc" means that you need to go to
www.mirc.com and download the program mirc. This is what is called an IRC client. IRC is like a super chat program. It is very hard to describe in writing, however,, I have drafted a fairly detailed set of instructions for setting up mirc, authenticating and self-perfoming. So once, you have downloaded mirc, please contact me (AIM s/n is jackel91) and I can send you the instructions.
Now that you have the map pack, you need to install it in your cstrike directory. I believe that the map pack is an .exe file. The easiest thing to do if you are unsure of the directory structure of cs, is to simply run the file and extract everything to a temporary folder. Then copy and paste all of the extracted files into your cstrike directory making sure that if a file is in a folder called 'Maps' in your extracted folder, that you transfer it into the 'Maps' folder in your cstrike directory. That goes for all files. Once you have done that you will be able to play all cz maps and Windex's new map.
/Night