Support includes documentation, access to forums and email support (for developer license). There is a wide range of tutorials for all products both as textual with examples or video tutorials. Even without premium support you will be able to access some of the the tutorials including many general WordPress tips and tricks based on practical solutions. Tutorials are also created based on the needs of premium users.
Access to premium support forum is available only if you have valid product license. Depending on the license, you will be able to access subforums related to products licenses you own. Also, developer licenses will allow you to use email support system. Forum will help you solve problems you might have, help you with customizations of plugins and themes or help with other general WordPress related problems.