The excellent plugin Widgets Reloaded by Justin Tadlock can come very much in handy when running the Notes Blog Core theme. Especially when you want a submenu in your header, using the Submenu widget area, and you want to base it on Pages.
First of all, remember that you can’t use the default Pages widget in the Submenu widget area, that will look awful since it always outputs a
h2 title, even when you input nothing at all. Luckily, the advanced Pages widget, which you’ll get access to after having installed Widgets Reloaded, doesn’t do that, so all you need to do is add that, and set depth to 1 (ie just show the top level Pages), and then you’re good to go.
This is an excellent option to the text widget method previously mentioned. Which of these you choose depends on the needs of your site, of course.