BossFight is an addon that will explain a boss fight strategy in your chat window. It can also tell you all of the boss' abilities that you need to know about. You can send the explanations only to yourself, to /say, /party, /raid, /guild, /whisper, or to a Realid friend.
Type /bf or /bossfight to activate the addon at any time.
If you have a boss selected while typing /bf , then a Full description of the boss' abilities, and/or and full description of the strategy for beating that boss will be displayed.
If you have nothing selected as a target, then your options menu should open up. In the options, you can set the messages to go to whomever you would like. You can also select a boss from the dropdown lists for an explanation if you are not currently near the boss.