Where will you begin? The Ferries have different feeder routes which you can see here: http://www.dot.state.ak.us/amhs/services/portinfo/index.html

Probably, the most popular is the inside passage. I’ve been on the ferry from Juneau, to Haines, Skagway, back to Juneau and over to Sitka, down to Wrangell and ending in Ketchikan.
Here’s my entry for this:
http://www.43places.com/entries/view/978653

If anything, I wish we had more time as I would have liked to go to Glacier Bay and a few other places.

It’s a great way to travel and not difficult at all. You can bring your own tent and pitch it on the upper deck or you can sleep in lounge chairs in the solarium (remember it gets dark very late and isn’t dark long in summer!)
or most ships have berths you can reserve. The nice thing with the berths are the shower and private bathroom.

The foods okay…most people do a mix of buying food and bringing along a cooler.

Most of the ships have narrated parts from either the Crew or a naturalist in summer.
Hope this helps you a bit more. Let me know if you have further questions.