Pulling from WP

so i’ve never really used WP, but I am redesigning my website…

http://craniumdesigns.com/NEW/cranium.html

I want to install WP in /blog, not the root directory. Can I still pull data from WP into the root home page with the right code? Or do I HAVE to install in the root directory?

Like in that design, I want the most recent post up on the top, and a list of recent articles in the lower right area.