Understanding Note Types

I'm trying setup and use WWF to create both standard forums (users read and post replies) and static Frequently Asked Questions section/s and static "How To" sections which pertain to my company's products.  I would like the FAQs & How To's sections to never expire and only allow admins to post to them.  I'm thinking I just need to understand the functional difference between notes, sticky notes, and announcements, etc. to accomplish the desired result.

Is there a place here (or can someone list) that lists or defines the functionality of each of the post types and what "closing" a post does?

I have successfully created group names and modified permissions for each individual forum and have accomplished the desired the functionality.  I'm just not clear on understanding the simple bits of what the functional differences are between notes, sticky notes, and announcements, etc.

Thanks