Yeah I think everyone doing a first aid course couldn't hurt. I think everyone should at least know the basics of CPR. You can glean the basics of CPR simply by googling it. I did put a fair bit of work in a while ago about what to do in the event of an OD with a couple of the American mods but I forget where it is saved now.
That advert with Vinny Jones that was on TV not so long back was a good one regarding CPR in that the fundamentals are straightforward i.e. Push down hard on the centre of the chest with one hand over the other to the rhythm of "staying alive"....and forget about rescue breaths....leave that to the professionals. All you need to do is keep the heart pumping the blood around the body as there should still be enough oxygenated blood in the body that if you can keep it pumping to the brain the person should still avoid permanent brain injury should they be able to be brought round.
The one thing I find personally is that all the CPR demos in the world cant replicate the element of sheer terror that cones with giving CPR for real as if it has come to the point that CPR is necessary then the person is in effect dead and sometimes the urge to panic is overwhelming.