How it works is:
1. You download the ModAdder.
2. You download all the mods into the same directory that you downloaded the MCModAdder.exe file.
3. Run the MCModAdder.exe
4. Make sure all the mods are listed.
5. Find your minecraft.jar directory (must be a clean, un-modded minecraft.jar. You can force Minecraft to update to get a clean Jar.)
6. Press Add Mods.
7. Play Minecraft!