A translation is necessary even if you are going to sing in French! It is difficult to sing when you don't know what you are saying. I will translate:

A la Rochelle est arrivé(at La Rochelle arrived)
Roulez, jeunes gens, roulez (Roll, young men, roll)
Un beau navire chargé de blé (a handsome ship full of wheat)
J'ai mis l'oiseau dans la cage, (I put the bird in the cage)
mais l'oiseau s'est envolé (but the bird flew away)

Trois belles dames vont marchander (three beautiful ladies went to haggle (at the market)
Marin, marin, combien ton blé ?(Sailor, sailor, how much is your wheat?)

Embarquez, belle, vous le saurez (Come aboard lady, and you will see)
La plus jeune eu le pied levee(the youngest had her foot lifted (to come aboard, I assume)

Le capitaine s'est ecrie, (the captain cried,)
"Larguez devant, larguez derriere!"(unfurl in front,
unfurl behind)
"Larguez les focs, les voiles d'ete!"(unfurl the jib, the summer sails)
La belle s'est mis a pleurer (the beautiful girl started to cry)

"Qu'avez vous donc la belle a pleurer?" (What's the matter, weeping lady?)
"Vous avez eu mon pucelage!" (You have had my virginity)

"Vous avez eu mon pucelage,
Mais je n'ai pas eu votr' argent!"(But I haven't had your money!)


Here is a word list:
est arrivé - has arrived
navire - ship
chargé - loaded
blé - wheat
J'ai mis - I have put
l'oiseau - the bird
s'est envolé - is flown
Trois belles dames - three beautiful ladies
vont - went
marchander - to haggle
combien - how much
ton - your
Embarquez - embark
vous - you
saurez - will see
La plus jeune - the most young
eu - had
pied levee - foot up
s'est ecrie - cried (s'est is the helper verb)
Larguez - unfurl
devant - in front
derriere - behind (but you knew that, didn't you? ;-)
focs - jibs
voiles d'ete - sails of summer
s'est mis a pleurer - started to cry (literally, put to crying)
Qu'avez vous - What's the matter (literally, what have you)
donc - then
pleurer - crying
Vous avez eu - you have had
mon pucelage - my virginity (or cherry, slang)
Mais - but
je n'ai pas eu - I haven't had (the French negation is "ne + verb + pas" so for example not singing would be ne chanter pas)
votr' - your
argent - money
I think I got everything in here. Let me know if I can clarify anything. Margo