How to adjoin wing skin to wing ribs?
The FAA offers a nice handbook on wing skin covering for fabric aircraft you can find here. They list, clips, screws, rivets and lace as the joining methods 


(source)


  Rib Lacing Cord 
  
  Rib lacing cord is used to lace the fabric to the wing
  ribs. It must be strong and applied as directed to safely transfer
  in-flight loads from the fabric to the ribs. Rib lacing cord is
  available in a round or flat cross-section. The round cord is easier
  to use than the flat lacing, but if installed properly, the flat
  lacing results in a smoother finish over the ribs.


In some cases, or even in adition to other methods fabric cement may be used. 


  Fabric Cement
  
  Modern fabric covering systems utilize special fabric
  cement to attach the fabric to the airframe. There are various types
  of cement. Figure 3-9In addition to good adhesion qualities,
  flexibility, and long life, fabric cements must be compatible