To go to the categories view, click "All courses" at the bottom of the "My Courses" block on the front page.
This takes you to the category view. At the bottom of any of these categories, you will see a "Request a Course" button (note: You do not need to be in the correct category to request the course, you will get to choose the category for your course in the request form)
(Clicking the button above will also go to the request form)
Follow the "Request a course" link in the drop down menu at the top.