Hi Marc,
Like da guys say, landmania is the place for info...
Last time I did this, you needed a 'quitus fiscale' from the local tax office (it's free, and certifies that the tax you don't owe has not been paid, if you see what I mean); an 'attestation de conformité' from LR France (whose number was 01 61 01 62 61; they will want a copy of the V5 + a few other pieces of simple info + a cheque for €125); a valid 'controle technique' (like expat69 says, no worries there if not modified, 'cept you may have to change yr headlights). Once you've got all those bits of paper together, a trip to the guichet at the local prefecture (where you need to fill out another form) should be enough to get you a new French reg, opening the path to parking tickets, speeding fines etc etc...
Bonne chance
Giles