I think the problem is that at the moment they only have summer class info up. Is that it? Well you can see on that page january (already passed) and february (inscription also already passed) dates, but they don´t show you when regular courses start. They should start in march, around the 3rd week or so. So I´d imagine their registration is like the 2nd week of March....if you really want to take classes there, make sure to get there early, because there are limited spaces and they often fill up!
I think you can usually choose between regular and intensive. Regular being something like 4 hours a week and intensive being more like 8. I´m not sure though, so you should wait for them to put the exact info up. At any rate, its much fewer hours a week than most spanish schools (and of course much cheaper!). I think one course is around 300 or 400 dollars (which would be for 4 months, 4 hours a week, somethin like that. it´s really one of the cheapest options for spanish classes).
I´ve never taken a spanish course there so I can´t really give any advice to whether it´s good or not, I´ve heard both good and bad things. I took a german class at the UBA and I liked it alright, but it wasn´t amazing either (it was, however, very cheap. you´ll be slightly angered to know that their spanish classes are more than twice the price of any other language class. foreigner fee.)
Hope that helps! Check back on the page igor sent you later, they should have information up for the semester starting in march.