Sitewide Navigational Internal Link Structure

Choosing between 2 sitewide nav structure for best link flow

[brill]

Hello!

I am currently trying to redo the internal link structure/flow for a large dynamic ecommerce site. We have 30,000+ pages, the majority being product pages.

My site’s structure:
Index>Department>Category>Style>Product

I am looking for some advice/best-practice in regard to the following questions:

1. We have 2 (or 3) site wide navigational elements:

--Top Nav: dhtml/CSS drop down menu with 140 links contained in 10 drop downs
--Left Side Nav: sitemapish looking list of our important categories and subpages, with 140 links in total
(--Breadcrumbs)

Is having 3 site wide navigational elements detrimental to proper link flow?
Should I only have one link per URL per page? (If so then something has to be done about the left nav)
My gut says that I should nofollow/javascript the left nav, but I am kind of at a loss here.

2. Having the dhtml menu site wide means that every page links to every category page, is this ideal? Or should I do something about this? My gut says that every category should NOT link to every other category but only those categories that are closely related.

Thank you for any help you may have.

-brill

[edited by: martinibuster at 7:55 pm (utc) on Oct. 26, 2007]
[edit reason] Removed URL [/edit]

[caveman]

A little more info might help. You mentioned 140 links twice, once in the context of important cat's and subpages. You do that ... twice? Or are those not the same set of 140 links?

From what you're saying, there may be a better way to tackle it.

Have you seen this Themes [webmasterworld.com] thread, especially BT's post? It doesn't directly answer your question, but it's very related. :)

[brill]

Basically it boils down to my site having 2 navigations, a top drop down and a left nav (which is mainly for usability's sake). Each has 140+ internal links pointing 2nd level category pages. My question is, does this duplication of links hurt our internal link flow or doesn't it really matter. If having 2 sets of the same links hurts and confuses the spiders, then I want to take the best course of action to approach the best practice.