When you go to the main Library page you'll see a grey box with blue tabs at the top. The default grey (active) tab is "Catalyst," which searches everything the library has (or can probably get access to).
To search more specifically click one of the blue tabs. You can, for example, find this Research Guide under the "Guides" tab all the way to the right of the box. You can type in the course number or title, or you can click the "Course Guides" dropdown and scroll to the bottom of the list to the Writing listings.