Here is a simple way to make a navigation bar for you blog without any blogger hacks. No codes need to be added to your blogger template. You can create a simple navigation bar just by clicking "Add a gadget" function.
And replace the http://yourname.blogspot.com/pagename with the URL of the webpage/post that you want to be linked and replace the word label with your desired name/label. You can paste more codes as shown in image below and edit the codes.
Save the gadget box. This is how the navigation bar will look like below your blog's header.