Start in the same places you would at home. It is up to you, where do you meet women at home? While I was in Argentina, I met women in the supermarket(asked which wine they would reccomend), the plazas, and partying at night.
I found the girls in B.A. to be beautiful but many seem to suffer from G.P.S.
Golden ***** Syndrome was actually developed in the United States but has been transmitted across the world via human interaction, world wide media influence, etc. Add to this the "Che" air of superiority, I believe the term "criado" was used by a colombian friend of mine, and you may find yourself with a very high-maintenance, beautiful date.
Do you tango? Salsa? This always works.
Of the countries I've been to in Latin America, I enjoyed Argentina quite a bit, but the women like the traditional dating schema. If you are looking for wild ONS, head north to Brazil.
If you'll be there a while, just get the numbers and put in the leg work.
If you want easy access to model-quality women in the mean time look up
"Blacks". If your personal standards or morals do not allow you to exchange pesos for pooh-nanny you will probably enjoy the dating options of the country anyways.
I usually just walked around and talked to the women I wanted to speak to. As far as the clubs go, they are good.
Several good friends of mine have had similar experiences with the women there. Fun to look at but sometimes difficult to touch. It's odd though because I've enjoyed the company of several Argetnian women outside of Argentina with almost no work put in on my part-I'll chalk it up to their vacation.
Enjoy yourself.