One way you might want to customize your Sharepoint home page is to add your company logo to an "Image" web part displayed on the page - in fact, the team site template comes with a "site image" preconfigured on the page. You can change the image presented here by putting the page into edit mode, then edit the "Site Logo" web part, and select the logo. It can be any logo, accessible from anywhere, of any recognized graphic type. Very flexible.
And then they turn right around and bite you in the butt, because if you have a ...