Porting phonegap apps to Worklight is often pretty straight forward. The contents of index.html -> Body go into the Worklight App's main HTML -> Body. If you have scripts and css links in the head, those need to be moved over too ... but you don't need to load cordova.js. The Worklight Framework will take care of that for you. It will also by default load jQuery, but you can override the version of jQuery used by your app code if you wish.
If you have processing in a deviceready handler, that should be moved to wlCommonInit. And the rest of the app artifacts should be moved to the correct relative position under the Worklight App's common folder.
After that, you will have to deal with details based on the details of the particular app you are porting, but that should get you started.