Hi Erin,
1. You can turn off the top level navigation for every individual page. Under the inspector window, click on the page icon (the second tab on top) and uncheck "Include page in navigation menu".
2. To create a "like-style" image/thumbnail" I would suggest first to make your photo album page. Once you have some photos in there, and have chosen a frame style (under the graphics tab - in the inspector - the tab with the square and circle), I would take a screen shot of the first photo. The best way to do this is to hold down the shift key, the apple key and then the 4 key. This will bring up some crosshairs - then, click and drag from the top left corner to the bottom right corner to get the photo completely selected. When you release the mouse, you will hear a camera sound. The photo then should show up on your desktop. Do this for each album.
3. Now, you can create an index page. Drag your "screenshot" thumbnails into the page in iWeb, lay them out how you want, then add hyperlinks to the thumbnails that point to your album. This is done by selecting the thumbnail, then in the inspector window, select the last tab (the blue circle with the arrow). Check the box "enable as a hyperlink" then select "One of my Pages", then select which page your album is.
Hope this helps.
Cobe