I noticed some blog sites which publish new post every 15 minutes, but their page rank is still low (PR=1). I think they want to post as many contents for adsense strategy. Some other site, they post >50+ articles per day. So, How many good content posts you can create in single day, before it is considered excessive by Google? Does google penalize excessive posting?
You really don't need to post so many posts, in fact, value is the king. Even you can only post one article per week, if the content is good, you are fine.