Gina Madsen is one of the really bright small business attorneys in Nevada. She recently asked me to write an article on a 'real-life' situation - and I chose the concept of firing an at-will employee.
Even though most states abide by at-will concepts (you can fire an employee at any time for any reason - other than a few exceptions), there are many compliance and management principles that should be followed.
Here's the blog on her great website - http://www.madsenlawoffice.com/