including posts on own layout

Parse error… on the link you gave.

There are many methods, try searching for integrate, displaying posts on website and similar keywords.

I don’t know which method to suggest since I don’t know exactly how do you plan to do it.

I assume you want the WP posts to appear in that middle area, right?
1. You can use The Loop
2. You can use a feedreader (serach for it here) and display your RSS feeds
3. Eventually, take a look at this guide:
http://www.transycan.net/blogtest/2005/07/05/integrate/