Consider your binder as a temporary storage place for lots of these things.

Meeting notes - go first into the inbox, then type them up, issue to people, add next actions to your action lists. Then once processed you can put them into storage - if you like keeping hardcopies make a folder, otherwise if you store electronic you can trash the hardcopy. I like to take the previous meeting notes to the next meeting, so before going to a meeting I would retrieve the hardcopy minutes/notes and put them in my folder under @agendas. Then after the meeting they would go back into storage. (I don't like to carry too much around, the folder can get too bulky if you do).

Projects/Goals - if you already know this and have it detailed elsewhere don't feel like you have to fill it. Put project support info in there - eg print outs of essential gantt charts or any other support material that is useful to have on hand at a meeting or out in the field.

Reference - I only carry a few things, I have 3 essential maps of the plant I work for and two process flow diagrams. Again, these are only key documents that I find useful to pull out when having a discussion and people have questions. Don't try to store too much.