How to create node navigation to cycle through nodes of specific content type
Have a look at these two modules:

Flippy
Custom Pagers

Custom Pagers is more versatile, but I found it buggy.
Another solution, more custom and flexible, would be creating a custom field in the content type (via hook_field_extra_fields() or Display Suite), and creating a custom query to get the next/previous node ids. If you prefer to go with the custom way but don't want to add a custom field, you can just preprocess the node and add the variable in your .tpl file.
Previous/Next API module could be used to get the node ids without the need to create the query yourself, apparently making the solution more scalable. It's still a -dev version though.