Unzip the files and transfer all the contents into the BGII - SoA folder. You will then need a utility such as Mod Organizer from TeamMac BG (the Spa & Grill) to actually put them in your game. A link to the Spa & Grill is on the Baldur's links page.
Also note that sometimes you will need to convert sounds that come with NPC mods from the .ogg format to .wav format. The reason for this is either that the Mac version of BG doesn't recognize ogg or because the compiler can't automatically convert them for Macs. To do this you will need a good audio conversion tool. I recommend Amadeus II as it is the best one to do this that I have found. All you have to do is once all your mods are installed:
1. Open your sounds folder in the BGII directory
2. Select all of the .ogg files
3. Drag them onto the Amadeus icon
4. Convert them to .wav (I have Amadeus configured to use .wav as default)
5. Save them in the same directory
6. Delete all the .ogg files
7. Voila! Your NPCs will now have the ability of speech
Another note: Some mods are available only in Windows only .exe format (Hopefully this won't matter when Leopard is introduced with built in Boot Camp). Here is how you can use those:
1. Extract the .exe file using StuffIt Expander
2. Make a zip archive of the folder that is created by doing this for backup purposes.
3. Follow steps 1-7 as stated above.
Sometimes StuffIt will give you a message that it can't extract the exe file. I think this is because the person that made the mod used a nonstandard way of making the executable. If this happens you will either have to extract the files using Virtual PC or find a good friend that uses a Windows machine to extract them for you.
