To the best of my knowledge the earliest source for the concept of maaseh avos siman l'banim is Ramban on Bereshis 12:6. I would like to know if there is an earlier source and what the parameters of this concept are. Are all actions of the Avos, good or bad, considered simanim for their children? If no, how can we determine which are included in this principle and which are not?
I think Tanchuma Parshas Lech Lecha 9 - which says א"ר יהושע דסכנין סימן נתן לו הקב"ה לאברהם שכל מה שאירע לו אירע לבניו is the earliest source.
Rabbi David Cohen has published 5 volumes of Maaseh Avos Siman L'banim where he goes through at length what is considered a Siman. It is way too long to answer over here. Here are links to his Sefarim.