I'd like to jump in to mention an excellent booklet I bought and read last week-end:
Prostitution, perspectives féministes, by Élaine Audet. It took me some time to realise that Audet is the founder of
Sisyphe, the French Canadian Feminist network you probably know already (English page
here). This little book summarizes the feminist argumentation against legalization (in Canada and elsewhere), with examples and stats from all over the world, as well as bibliographical references, the targeted readership being progressives who are still undecided and aren't aware of a feminist discourse that isn't pro-porn.
So, if you know any French-reading people who are in this case, this is a good way to present your position (it shouldn't take more than one or two hours to read), as well as an useful gift.