The "Layout" page lets you arrange and add cool gadgets to your blog.
To change a gadget you already put up select "Edit"
This is what you can do under the "Page Elements" tab:
Add gadgets. There are thousands of gadgets you can add: pictures, polls, Youtube, daily quotes, news reels, weather forecasts, following. Basically everything you can and want to add is right here.
After you have added a few you can rearrange them on your blog by moving your mouse over top of them and dragging them around. You can even move them onto areas that might be hidden at the top or bottom of your blog. Just drag them to the top or bottom until you see a dotted line show up and place it there.
Be sure to "Save" before you exit.
A label list can also be added here too. It will show up in the side bar as a list of all the "keywords" used in your blogs. You don't really have to have this list of labels, but make sure that when you write a blog that you add a few keywords. This makes it easier for people to find your blog when they are searching.
You will find this option at the bottom of your "Create post" page, in the gray bar around the writing area. Titled "Labels for this post" it has some examples of what your labels should look like and how they need to be typed in with commas in between each one.