Go and read how the pagerank algorithm works.

You should know that Google like websites who update their contents regularly. So don't stop updating your blog's contents. However, you should make sure the contents you update for your blog should be unique, original and useful. Select some proper keywords for your new blog posts, I believe you will have more keywords have better PR. Good luck!

Sounds like you're confusing Pagerank with ranking a page. The former is Google's metric to evaluate the importance of the website, ie. how much other sites link to it. Backlinks affect your rankings in the search engine.

So you're asking if you can get to the first page by posting a lot of articles. Being active is not a bad thing, but mindless posting probably isn't going to yield results. Try to target the right keywords, and write content that's engaging to your visitors and SEO optimized for Google. See that the internal linking is good within your site, and try to get other sites to link to your content too.