Credit cards here work exactly the same as they do in the US, however they are not as easy to get, which I don't think is necessarily such a bad idea.
The pitfalls with credit cards here are: 1) Some banks charge an "annual renewal" fee which can be hefty ($600 pesos), just to keep the account each year. 2) Some banks charge a monthly fee for "emisión de resumen" which is a monthly fee ($20-$30 pesos) just for them to issue a statement each month, and this is charged whether you get an electronic statement or a paper one sent by mail. This is where you have to be careful with because if you get a discount let's say for paying by credit card in 12 cuotas, and t's $200 pesos off the price of the item, you will end up paying (if they charge $30 each month for the statement) $360 just in fees, so using the 12 cuotas ends up costing you more (due to fees) than paying upfront for the item. 3) Some banks charge a "maintenance fee" just to keep the credit card account open, above and beyond maintenance fee charged for the savings / checking account you are required to keep open at the bank who issues the card.
This is one place where you should VERY CAREFULLY analyze the cardholder agreement before you decide to sign up for the card, and yes, compare banks also. Make sure you know what their fees are, here they can be VERY steep!