Entered fake WordPress address

As the topic says… in my exploration of WordPress, I accidentally changed the WordPress address setting in the General Options section.

It broke my site, and now I’d like to set it back, but for the life of me I cannot find where the configuration of settings such as this are stored. Any tips? I’d rather not reinstall, if possible.

Actually, and one more question: I use WordPress to edit static sections of a site (i.e. I do not use the “blog” functionality of it at all). I’ve created various “pages” and they work great. However, the front page of my site is where my blog posts would be – of which there are none, and so the 404 page shows. Is there a way to start at a certain page?