Google is re-scanning my site twice a week. Is that good or normal?
 

When I look at Google's cached version page of my website it changes twice a week with the new content.

Is that pretty normal, or is that really good, like theyre seeing my site has lots of content and is updated constantly?

pretty normal from what ive heard.

If you have good PR it will happens

All the SE's have adopted that practice for frequently updated pages. Yahoo is the most intense by my logs and scans almost continuously.