How do you link via the in an XHTML doc to a wordpress blog page ?

Hi guys and gals,
Ive created my website in xhtml/css, and then created a unique blog page on wordpress using the buddymatic child theme template.
My question is this, what filepath do I use to link from my main sites navigation to the wordpress blog ?
And where does the blog folder/files go on my server in relation to the html/css(main site contents) ?

Thanks all

Ben-is-jammmmmmmmmin