If this is a new page, you'll have to build to 100 fans before you can choose a custom URL. You should still choose an initial URL that reflects the page focus. Shorter is better.
You will be responsible for adding your contact info, the avatar picture, etc. Your page has a Wall and an Info tab that we cannot change.
Your Custom Page will have 2 tabs that follow. You can choose the name and the content for these tabs. Provide a link to a page on your blog or website that you would like mirrored on FB, ("About Us", "Meet the Team" or something similar). Not sure just enter - SEE ME and we'll talk about what you might want.
Additionally, your Custom Page will have an RSS Tab. You may automatically bring in the RSS feed from a couple of sites. To do so, provide the URL for those. What can you bring in? Your blog posts. Your Flickr Pictures or just a photo group. Your Twitter Stream. Most anything that has an open RSS can be brought in.
Here's what doesn't work in Facebook Pages: iframes and dynamic content. Some content might work but the form does not. In cases like that we can just direct them to a page on your site that does work.