How to add blogging functionality to a static website

To give a good answer we need more information. Does your friend actually want a blog or just to change information on his website regularly? HTML and technical proficiency? Windows? What is his current website hosting arrangement and what kind of upload access does he have?

http://www.blosxom.com/ is super easy and elegant: to add a post, you just put a text file in your blosxom folder. You can also use whatever html and css he already has with the template.

You might check out Cubescripts' $50 "http://www.cubescripts.com/cms-script.php" software package. I've heard good things about it. Another idea: Try http://www.webvanta.com/. They'll even take you all the way from PSD file to website. You do have to host with them, but it's not a bad deal.

Wordpress. Either move his entire site into Wordpress, or drop Wordpress into a /blog directory and add a link from the home page,

Does he want a full-blown blog, or just the ability to add news? If the former - well, I've deployed several Wordpress blogs and I'd recommend it. Just do what COD suggests. If it's just news, then something like http://grabaperch.com/features/multi-regions (self-hosted) or SurrealCMS (hosted by them) might suffice. If he really doesn't mind have the blog off-site, then he could register something like mychiropraticbusiness.wordpress.com and just link to it. Almost zero set-up.

Oh, how cute. It looks like Perch has a http://grabaperch.com/add-ons/apps/blog.

> What is his current website hosting arrangement and what kind of upload access does he have? We definitely need to know this before we can proceed.

How about a Tumblr account? You could write the blog on there, and then just insert it into a page on your site using their javascript embed widget, like so: <script type="text/javascript" src="http://yourusername.tumblr.com/js"></script> You can style it with css, etc.