Just a quick post to elaborate on the install for mac users. Feel free to embed into the OP, or don’t.
 Download the pack and place it on your desktop for easy access.
 Double click the pack, and under normal circumstances, it will extract itself into a folder on the desktop. If it doesn’t, use whatever zip program you have about to extract the archive to the desktop.
 MAKE SURE you have a vanilla minecraft.jar. If you don’t know how to do this, launch minecraft but before logging in, click the “options” button. Then select “Force Update!” and log in. This will wipe your minecraft.jar and download the latest and greatest version of Minecraft for you.
 Open up Terminal.app, type in “cd ” (including the space) and then drag in the folder, which was extracted to your desktop, onto the terminal application. Press Enter and then afterwards type in “sh modpack.sh” and press Enter.
 Follow the instructions in the installer. If you want the whole package, press N, then Enter, Y and then Enter again. It’ll install everything and you can exit terminal afterwards.
 Have a beer, or some popcorn, perhaps even a soda – if you don’t like beer or are too young to drink it.
 Par… wait..
 Open Minecraft; Connect to MCNSA and THEN party!
If, at any point in this, you fail to comprehend the simplicity of this guide, please do take a look at this video: http://cl.ly/Gbaz