Vicky, spring and early summer are the best times for seeding all forms of bahia, of which Argentine is one, so this is prime time. Bahia germinates slowly, so you must be prepared to irrigate until it is established. The University of Florida Extension Service recommends using scarified seed, which has been chemically treated to enable faster germination, when possible.
See this general article on bahia:
And this article on proper site preparation:
you're asking about Argentine bahia grass, right? not St Augustine grass.
the slow germination means you have to constantly look out for weeds to pull in it