First of all, anything that your students post to your classroom can be seen in that classroom space. Posts will appear chronologically, beneath any posts that are "sticky at top of list." You can view content chronologically by scrolling through your classroom posts.
To give yourself more options for how to sort through content, click "Find Stuff" in the top tool bar.
This will take you to a page where you are given the option to view pieces as a table, full nodes, portfolio view, comments only, or arranged in a table divided up by author.
In each of these views, you can filter through posts by classroom, tag, author, and whether or not the piece is published on the site, or just saved. You can filter by a combination of any of these fields. (Teachers have the ability to see things that aren't 'published.' Other students do not have that ability.)
NOTE: ((In all tables, by clicking on a column heading, you can sort what is displayed by alphabetical or chronological order, depending on which is possible. Clicking again will invert the sort; i.e. 'newest to oldest' changes to 'oldest to newest'.))
You can also perform a keyword search, where you can search for any keywords or tags you've used, which is useful for finding the responses to a specific assignment.