A sitemap is a page that displays all pages of your site in one place. A dynamic sitemap is a sitemap that automatically updates whenever you add a new page to a site. This is a huge timesaver as you have to do this manually if the sitemap isn't dynamic.
The dynamic sitemap here was created by BANS forum member WebMogul. He is kindly giving away this mod and it is a really great one. He does include instructions but there has been some confusion so I am clarifying here.
Upload the sitemap.php page to your web site's root folder. This will be the folder where your index.php page is located.
Edit the .htaccess file from your web server.
TIP: Quite a few people are getting tripped up here. The .htaccess file is usually hidden from view, causing people to think they don't have this file. Probably the easiest way to edit this is:
Find the .htaccess file that came with your purchased BANS software.
Make a copy of the original .htaccess before you edit it so you can always revert back if you make a mistake.
Edit the .htaccess file (as explained below). You can edit the file by right-clicking it and selecting, "Open As Text" (this is the option I have for Windows XP; your option may differ slightly).
Upload the modified .htaccess file to your root folder (the same folder you uploaded sitemap.php to).
Click here to view the .htaccess file before and after this edit to see what your .htaccess file should look like.
Save the edited .htaccess in your web site's root folder (the same folder you uploaded sitemap.php to).
View your newly created dynamic sitemap at http://<your site name>/sitemap.xml. You should see your site's content pages being listed before the store pages.
TIP: http://<your site name>/sitemap.xml and http://<your site name>/sitemap.php should show the same information.
Click here to view one my store's dynamic sitemaps created with this mod.
Submit your sitemap.xml to Google's Webmaster Tools. If you yet have an account with Google's Webmaster Tools you can create one at www.google.com/webmasters/tools/.
Submit your sitemap.xml to any other search engine that accepts them.
Potential Problem: When I first did this I found that my sitemap wasn't accurate. There were many pages missing. It turns out I had previously created a sitemap.xml page and this was overwriting the one I was now trying to create.
I resolved this by deleting the page from my server (I did this from my hosting site's File Manager) and starting from scratch. You can tell your sitemap is working if it says, "<!-- Generated by WebMogul's BANS sitemap generator: http://mogul.webmogulenterprises.com -->"
at the top. The color and alignment of this message may vary but not the wording.