Forum Moderators: open
Essentialy on each page there is a navbar to all areas in the site, plus links back to the main index page and any local index pages, plus a mini index of the local page cluster. There is also a site map.
More: you can do a lot of good to your site if you link internaly following theme structures.
Allway worth to read this related stuff:
Theme Pyramids [searchengineworld.com]
Successful Site in 12 Months with Google Alone [webmasterworld.com]
I'm not worried about internal linking, just being cautious.
Last month I changed and increased my internal linking structure and it raised the PR throughout the site. So its entirely possible that some change I might make could inadvertently destroy all that. If duplicate linkings are a potential problem then I would eliminate them.
Harry