some kinds of spermicide made hubbies lips numb.... but we found a kind that didn't).
You just squirt it around the rim and in the middle. Then you fold the diaphram up in half - it a latex thing with a ring - and in it goes. You can do this several hours before sex but we usually didn't. I didn't think it was any more disruptive than a condom but I liked it a lot better.
You need to have a diaphram re-fitted if you change weight or give birth.
I will also second the discussion of FAM. Why didn't anyone tell me and why is it lumped with The Rhythm Method?