Hi Brian
I'm the author of the Url Master module that was suggested to you. With this module, you have two choices to go from your 'old' site to your new site.
1) You can just setup the DNN pages to match your 'old' site pages. For example, contact.htm -> you'd create a DNN page called 'contact'. You would then set the Url Master module to use '.htm' for the site extension, and the old urls would just work as you'd expect. Note that you'd have to do a 1:1 mapping of old urls to new DNN pages. In this case, there's no redirect, you're just setting up your new site to use the old urls.
2) You can redirect the old urls to their new equivalents. For your 'contacts.htm' example, you'd pick the page you'd like the contacts to go to (for example, 'Contact Us'). Then you'd go to the 'page urls' page that the Url Master module installs on your site, and in that page you'd select the 'new' page (contact us) and enter in the 'old' url (contact.htm). Save the changes, and now, when you request 'contact.htm' you will get 301 redirected to 'contact-us.aspx'.
Note that in both cases you'll have to map the .htm variable to the ASP.NET extension in the IIS configuration, so that ASP.NET responds to a .htm request. You'll also have to modify the standard Url Master regex to remove \.htm and \,html from the 'ignore Regex' field (normally the module ignores the .htm requests)
You can download a free trial and setup your site from http://www.ifinity.com.au/products/Url_Master_DNN_SEO_Urls/ - you should be able to get the redirects going in about 10 or so minutes.
regards
Bruce