Upgrade your blog with the steps found on this page from the WordPress codex:
Special link for updating WordPress.
Take each step in turn and make sure to backup everything and you’ll be ok.
After you update your blog to the most recent version of WordPress, why not try a new theme? The theme viewer over at WordPress has grown to include a wide selection of themes. All searchable by color scheme, number of columns, fixed width or fluid width, widget-ready, and so on!