Why limited? Where did you look? There is comprehensive user documentation and training modules in the following websites:
Regardless, there is no such thing as "controlling a browser's Back and Refresh buttons".
These buttons are provided by the mobile browser and are out of scope for whatever is running within.
It would be more beneficial for you to edit the question and explain your specific scenario - what it is that you are actually trying to accomplish.
In Worklight, you have WL.Client.reloadApp
, for example, which can be used to refresh the web resources displayed. As for "back button"-like functionality, this can only be determined once you explain what you are trying to accomplish.
Additionally, keep in mind that while Worklight provides some API methods for controlling UI elements, it does so only to a certain degree and only for elements that are most common to all mobile environments (iOS, Android, ... for example, creating a tabbar); when you develop a web app for the Mobile Web environment, you cannot control via the app things like the Refresh button that the mobile browser supplies.
Lastly, you can and probably should opt to 3rd party frameworks such as jQuery Mobile and the like for the UI aspect in your Worklight application.