Drupal Blog post add approval before publishing

Hi to all, I'm having a hard time figuring out how to add approval function for the blog posts submitted by my clients/members of the site.
What i want to happen is that every time they add a post on blog it should be under pending state needs approval then it will notify me via email or something that someone has submitted a blog posts so that i can review it and approve.
anyone tried doing it ? please help i need this on my site badly.

Thanks in advance guys.