With a relatively new site for accountants I have made changes from Caps to lowercase for level 4 descriptions, creating thousands of pages not found. I believe that this is punishing my site, and the effects may last for many months. Will using Google Sitemaps extensively, address this problem, or is there freeware (or similar) that might assit me deal with the rediversion of pages in Webmaster Tools or in the htaccess file? Thank you for your assistance.
If you have thousands of pages not found I think that I'd redo the whole site so that the search engines can't see that.
i actually don't get what you mean. it sounds like a simple problem though. detailed description and i'll try to help you.
Sitemap has nothing to do with your problem. Sitemap is a way to show Google where all your content is and make sure that your pages are indexed.