While it is possible to change the spacing by adding <br /> tags in the code, that is a rather coarse method.
You will get much finer control over the page appearance by editing your stylesheet
(/includes/templates/your_template/css/stylesheet.css), and it will be easier to adjust.
For example, find in your stylesheet.navNextPrevList { display:inline; white-space:nowrap; padding:0 1em; list-style-type:none; position:relative; }and add below it```
.navNextPrevWrapper {margin-bottom: 1.5em;}
.navNextPrevCounter {margin-bottom: 1.5em;}
Get Firefox and its Web Developer extension. This will help you to find the ids/classes to apply styling to, and let you test-edit your stylesheet and see the results instantly.