Adding buttons to editor?

How do I add custom buttons to the editor, for all those personal stylingtags I make..

Example, press og a button in the editor prints:
<span class=”upupandaway”>upupandaway</span>

..or:

..where I get a popup asking for the Alternative text (and title if not possible to fill these both out in one command) and the Name of the target (to be added after the # symbol)