IndustrialCraftConfig.txt that comes with the IndustrialCraft mod download needs to be copied into the .minecraft folder (NOT minecraft.jar)
The "#enableNano=true" line in IndustrialCraftConfig.txt must have the "#" removed, then the file saved
fm.class from the Experimental Nanosuit File folder must be copied into minecraft.jar (you should know how to do this if you've successfully installed the IndustrialCraft mod in the first place)