most basic navigation

If you go to settings, appearance, menus and play around a bit you will figure it out.

http://codex.wordpress.org/WordPress_Menu_User_Guide

When you are under settings, appearance, menus on your left hand side you will see a box with Tabs that say Pages, Catagories etc. Be sure to click view all, select the pages you want on your menu and click add to menu.

They will be added to the bottom of the list in the main field and now you can drag them to where you want them in your display.

If you slide them up/down the appear sooner/later in your navigation bar.
If you slide them right/left they become either a top, sub or sub sub link.

Hope that helps