plan the organization of site so viewers can find the exact set of posts they want

I need help understanding how to organize a site, pleased. The blog follows voyages. On each voyage the single blogger makes posts that are either (class? category? tag?) Position, Captains Log or Photos.

The end result will let visitors
navigate from any place on the site to anywhere else.

Examples, under Photos be able to choose from a list of location, the result displaying only Photos (no positions or logs) from that location. Or, reading in the Captain's Log the visitor would see onlys Captain's Log posts and no position or photo posts.

I think that taxonomy, which I don't understand even the word, and categories and tags have something to do what I need, in fact can easily accomplish it but I don't have any understanding of how nor overview or plan.

So far, I'm trying this. Top level items in my menu; Voyages, Capt's Log, Photos, Position.
Subitems under Voyages include (for example) 2013 Bali, 2012 Fiji, 1999 Tierra del Fuego. Under each of those Voyages (2013, 2012 etc) are futher subcategories: Capt's Log, Photos and Position.

OK so I start a new voyage. I add a new category, say 2013 Malta, making it's parent Voyages. Add three more categories (Capt's Log, Photos and Position) all parented by 2013 Malta. Then I'd have to modify my menu, adding 2013 Malta as a child of Voyages and adding Capt's Log, Photos and Position as children of 2013 Malta. Creating my first Capt's Log post on th is, I would assign it to the following categories: top level (Capt's Log), 2nd level child Capt's Log.

From then on it would be easy adding each new post assigning to the right categories and levels but before starting this requires making new categories and new menu items.

Is there a better way, to build a navigation system giving choices built on qualifiers like:

2013 Malta+photos
photos+2013
logs+monthyear (would exclude photos, positions)
every possible permutation.

Please tell me somebody, anybody, has a plugin to do this easily, or help me get an overarching plan on how to approach this.

Thanks in advance.