First you need to decide which resource should be a featured resource, if you know which one, go to that resource and click on the three dots on the right top corner, a submenu will be opened:
now select Featured resource. If you want to mark multiple resources as featured at once you can tick the checkbox on each resource (in the example it is point 1 and 2) on the resource overview page and select featured in the dropdown menu (3) and press then Go (4).
This resource will than be shown as a featured resource on the resource overview. If you want to get this as well on the forum overview page, you need to place and create a widget called XFRM: Feaured resources:
That's it.