While you cannot activate more than one theme at a time – It is possible to have a different look for every static page of your site – you accomplish this by creating page templates for your static pages – then style that particular template using CSS/graphics, etc. (making sure you assign the template to it’s page in the WP admin panel – find that option to configure this in the Page Template drop down under Manage / Pages – then click ‘edit’ for the page you want to assign the template too – – you’ll find the “Page Template” dropdown menu there.)
You can set completely different looks/layouts on each page if you wanted to.. all within the same theme, using the same stylesheet, etc.
I believe the book explains the use of static page templates in Chapter 16 ??