I've got a project website and added your blog towards the website. However I don't want it do be considered a exterior blog, it ought to be inside the site.

I don't want to grow your blog on myself but recommended to make use of some type of blog module designed in php. I personally use zend framework for my project site.

Are you able to provice some links or ideas?

Can you really use wordpess?

See Integrating WordPress with Your Website « WordPress Codex regarding how to range from the Wordpress blog header and put the publish/page loop in your design.