Interlinked Website Structure

Realistically this structure can only be achieved for relatively small sites since every page links to every other page. If you have a 250+ page website it looks a mess to link every page to every other (250+ links from every page!!) and so it is not advisable (not a good idea for SEO reasons either).
This brings us to the question when should a site be completely interlinked? Difficult to give a clear cut answer since there will be small sites where interlinked is not suitable. A very general rule would be above 100 pages and don’t interlink, below 30 pages interlink completely.
This leaves a huge number of sites between 30 and 100 pages where interlinking may or may not be a good idea. To decide if interlinking is a good idea look at the anchor text of what the links will be. If most of the links are of a similar theme (anchor text wise) then it’s probably a good idea to interlink.
In other words look to see if the anchor text will improve the general optimization of most pages of your web site. If you have a site that almost every page is about a similar subject (uses similar phrases), for example, if one page is about SEO Services another about SEO Consultant and a third about SEO Tutorial etc… you can see having each link to one another will help with SERPs related to SEO. You want all these pages to link together in someway, the easiest would be to interlink via a menu.

Regards
Rohit Mehra