Basic Web Pages are the easiest to setup and get you going in SharePoint right away.  Here is how to do it:
From the main site collection, click the Site Actions button and choose Create from the dropdown
Under Web Pages on the next screen, click Basic Page.
 
Give the Basic Page a name and choose where you would like it saved. Then click Create.
 
After you click Create, the page will open along with the Rich Text Editor window in front of it.  Type whatever you would like to display on the page.  The toolbar also gives you options to change fonts, add pictures, etc.
 
Click save and your work appears on the page.  You have now created your first custom page.