After installing the plugin you will see a ‘Questions’ tab added to your WordPress admin area. The only section initially available is settings. In the settings area you need to determine who view questions and answers, edit questions questions and answers and delete other users submissions. By default all roles are set with no permissions, therefore you need to go through every role and set what they can do. I found this very strange, at the very least you would expect admins to be have full control over everything. As it stands, you need to give yourself permission to use the plugin.
After setting the permissions correctly you are supposed to be able to see your site at www.yoursite.com/questions/ and the page where users can ask a question at www.yoursite.com/questions/ask. Unfortunately, this does not seem to happen on its own. Via the support forums I established that you need to go to your permalinks page (at http://www.yoursite.com/wp-admin/options-permalink.php) and re-save your permalink settings. This ensures that the plugin works correctly (bear this in mind as there is no information about this currently on the installation guide).
Once you have set the permissions and re-saved your permalink structure, you will set new links in your admin area to see all questions, add a question, add question tags and view all answers. I added a few questions to see how the plugin worked in practice and I must admit, I was fairly impressed. The default look is quite basic though this can be edited easily through your stylesheet.
Questions can be voted up and down and to avoid gaming, those who pose the question can vote on it themselves. The premium version of the plugin also has categories and allows anonymous users to post questions and answers but I believe that the lite version should be more than enough for most people.
If you are looking to add a questions and answers section to your website, I recommend checking Q & A out. You may also want to consider WP-Answers premium plugin (reviewed in September 2010) and the Sofa QandA premium theme (reviewed in April 2011).
Link: Q & A Lite WordPress Plugin