There is a "Description" element for each Test Case. This is where I put any kind of summary, pre-conditions, expected results, requirements, etc.
Double-click a test case. Click the 'Description' tab. One neat feature is that if this Description field contains any text, then mousing over the test case in the navigation tree will display a popup 'tool tip' style window that displays contents of the Description field.
Same concept exists for TestSuites and Project. I know of no such feature for individual test steps. Not sure I would want to have that level of detail cluttering my view.