What can I do to increase SEO while my site is under consruction?

I think you need something more than you have now, put a nice intro about your site, maybe even an about us style page. Tell the world what you are going to sell. Also get rid of the free page from Godaddy and host it properly with them. A few $'s spent now will start off your ranking process. If Google saw your page now, it would not hurry back!

 

I would build links, plus put up a paragraph (keyword rich, of course) about the site. Get it ranked while you're finishing up. It's nice and easy!