In Blogger, click on the Design option. From there, choose Page Elements, and Add a Gadget right under your header. Add the "Pages" gadget (under "Basics"). You probably want to have the "Automatically publish new pages" option checked. Save changes, and you have your navigation tabs. :) See? Super easy.
Now for adding pages (and tabs). You will automatically have a Homepage (of course--this is where all your amazing posts go!), but you probably want more than just that, which is why you're reading this post. Let's say you want to add an About Me page and tab. Just go to Posting, then Edit Pages. From there, you can add new pages, edit the ones you already have (but not the homepage--it is what it is) or click on "Learn more" to (are you ready for this?) learn more. So, click on New Page, and then write all about yourself!
And there you go! Super easy.
I have an idea about how to make customized navigation tabs. I'll let you know when I get it all worked out!