The only thing I can think of are AJAX, cgi and CSS3 as the how-to.
Navigation menus are getting more sophisticated, with a goal of being more intuitive. For usability, this is great. For SEO, it can present issues.
Drupal has forums...have you checked there?
It sounds like AJAX, cgi and CSS3 might require learning in a way not entirely unlike learning a new language, in which case they're beyond me. I'm doing my best with my limited knowledge on web design and through the use the basic wysiwyg-natured Drupal CMS.
Drupal does have forums but I absolutely abhor them.

I would like to implement multiple secondary menus, each of which are only accessible from specific pages within the site.
When doing this, be careful about keeping in signals for sense of place. Once a site alters its consistency, the user gets confused and frustrated, having to relearn the navigation. You can create a second level navigation scheme inside a hub (category, upper level) as long as there is an obvious path back up one level AND a fast escape route back "home".
At the moment, I have a main menu (at the top of the page) with the main internal links and, so far, one of the links includes a drop-down that displays a few categories related to that link.
After viewing a category, the page content has a new vertically-oriented menu (on the left side of the page) displaying the internal links related to that category. Although there is only the one side-menu, it has subsection pages linked within it (they are indented).
I'd like to have that menu horizontally-oriented and placed below the main menu that is at the top of the page, though I don't know how the indentations would work at that point.
Within the subsection pages of that side-menu there is need for another sub (or I guess sub-sub) section. This is where I'm getting a little concerned about ease of navigation: How do I implement those "sub-sub-pages," which are already contained within a category (or, really subcategory) of the site?
Here is a basic example of only a few of the menu items that I'm currently working on:
Main menu at the top
Main menu item - Musician (with drop-down)
Main menu drop-down item - Educator
Educator page contains side-menu
Side-menu item - Curriculum (with a list of indented items below it)
Side menu 1st-level-indented item - Program
Side menu 2nd-level-indented item - Phase 1
Side menu 3rd-level-indented item - Level 1
And here is where I'm concerned about ease of navigation versus bloated menus:
Side-menu item - Curriculum (with a list of indented items below it)
Side menu 1st-level-indented item - Courses
Side menu 2nd-level-indented item - Academics (there is a non-academic item, so this is required) (quick edit- this is an entire section)
Side menu 3rd-level-indented item - {specific subclassification of courses} (edit - this is necessary)
Side menu 4th-level-indented item - {specific course with summary} (quick edit- there are a lot of courses)
Side menu 5th-level-indented item - Syllabus
Side menu 5th-level-indented item - Schedule (too detailed to include in syllabus page)
...now, that's a lot of indentations. By that point, the Syllabus and Schedule pages are, let's see if I'm counting this right... main/musician, educator, curriculum, 1st, 2nd, 3rd, 4th, 5th level indentations...
eight levels of menu items.
Organization is key.
So is ease of navigation.
Bloatedness is the curse that must be avoided.
The trick is: How?
A.N.Onym - thank you for those links! As usual, you are the excellent resident Drupal Guru of Cre8asite.

For having specific menus on specific pages or pages of a specific category/taxonomy:
- create a menu with links
- go to blocks, find the menu
- edit the menu block to be displayed on specific pages (if there are few of them and they don't change), select a content type or find/install a module that'd restrict the filter to taxonomies (I like this approach better, it allows for much more precise filtering)
Perfect.

I now have the current secondary menu set-up and only displaying on certain pages.
Then again, I found the module that does what you want, but it doesn't have a 7.x version. Many more tabs modules don't have the 7.x version, too.
It seems there isn't much for Drupal 7 add-on features. I'm guessing v7 was only recently released. (?)
Maybe something like this? http://net.tutsplus....d-content-area/
CSS and scripting in general... all of that's beyond me.
Edited by Zylek, 30 April 2011 - 11:12 AM.