Right now, Actions module has some serious rough edges when it comes to usability: there is no help page to explain what the module does, the differntiatoin between Actions/ Actions module is very confusing, and you can assign actions which make no sense (when a user is logged in, publish a node??)
There are a group of us in #drupal now talking about how exactly we can do this, but since this is one of D6's killer features, we need to make sure it's easy enough to grasp for a typical site admin. Please feel free to jump in!
Concrete actions (ha ha!) that can be taken to solve this forthcoming...