Thanks. I've tried that, which does seem simple enough. But when I submit my Sitemap to google it comes back with an error 404.
I'm not sure what you are "submitting" ... it should be a textfile named something like "sitemap.xml" uploaded to your site ... generally the main page of the site your maping.
Then you just login to your google webmasters tools account and tell them where it is ... and I think you have to say it's in xml format too but I know it works and is really pretty straight forward :)
Anyways, here's a snipet of mine ... you just need to add your own url tags {as many as you need} and set your changefreq accordingly.
<?xml version="1.0" encoding="UTF-8"?>
<urlset
xmlns="http://www.sitemaps.org/schemas/sitemap/0.9"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://www.sitemaps.org/schemas/sitemap/0.9
http://www.sitemaps.org/schemas/sitemap/0.9/sitemap.xsd">
<url>
<loc>http://YOURDOMAIN.com/</loc>
<priority>0.5</priority>
<changefreq>weekly</changefreq>
</url>
<url>
<loc>http://YOURDOMAIN.com/forum/</loc>
<priority>0.5</priority>
<changefreq>daily</changefreq>
</url>
</urlset>
You should still look through http://www.sitemaps.org ... there are more tag options and tricks and tweaks but this should get you going in the right direction :)