Just got a copy of this little book from all rich publications; it's very good to be honest for a fiver.
There's a lot in there for bikes and it covers lots and lots of French traffic systems and laws. I was very surprised at what I didn't know.
Anyway,
I'd recommend you have a copy if you're doing a eurotrip - the explanation of all their penalty codes could save you if you get a tug.
www.allrich.co.uk seems the best place to order from.