Thanks for your help! Actually I figured it out last night before going to bed, which is a huge relief. Now onto other problems (i.e., converting away from tables, which is my next assignment).
I've found that the design view is only useful for getting a general picture of what the site will look like as well as preview. Before posting, one problem I noticed was that my CSS wasn't linked correctly to the page. After some other tweaking, the preview now looks almost right!