You're asking a couple of questions here, so I'm going to give a couple of answers. :)

1) This seems like a new page. If it's a completely new page you're introducing, look at the About Us contribution in the downloads area for an example of how to do this.
2) This seems like the modification of an existing page. If you're just including some code into an existing page, just use include or require. Put the new code as close as possible to the old code, in a template folder - mostly so you'll remember where you put it three months from now.

Hope this helps,
Scott