This bar can be removed if you want by placing a little bit of code in the blog template. Tricky but cunning!
Here is how to do it.
1. Firstly- seeing you have got rid of the Navigation Bar you still want a link to the Blogger log in page.
Go to your Overview and go to LAYOUT.
Click on add a gadget.
Scroll down the list til you get to LOGO. Click on the PLUS sign to add it.
Chose one of the LOGO colours that you like and click SAVE.
Now all you need to do is click on the Blogger logo and it will take you to the Blogger log in page.
2. Now go to the OVERVIEW, then go to LAYOUT.
Look for NAVBAR and click on edit.
Look for where it says OFF in the pop up box. Click and save it and your work is done!.
3. This is another way to get rid of the Navigation Bar using html.
Copy this bit of html code.
Then go to the OVERVIEW and go to the TEMPLATE.
Click on it. Then click on EDIT HTML.
You will get told to be careful but procede any way.
Usually you paste the code under the second dotty line. Each template can be slightly different.
Click PREVIEW to check of the navigation bar at the top has really gone.
If it has, click SAVE TEMPLATE- if it hasn't try the code somewhere else.
I would add once more that it is a good idea to preview the changes before you actually publish them in case you have put the code in the wrong place. If you muck it up just discard the changes and try again.