I prefer sleeves over tabs because I feel the quilt should get all the attention, not the hanging mechinism. For a hanging that size I would make the sleeve about 3/4" shorter on each side so you could have nails supporting each end of the rod. On larger hangings, I split the sleeve and use multiple nails.
Here are several web sitees with instructions:
http://www.quilttownusa.com/mom/sleevebeginners.htm
http://quilting.about.com/od/decorat...ilt_sleeve.htm
http://www.craftandfabriclinks.com/TIPS/hangsleeve.html
http://www.mccallsquilting.com/arthe...hangingsleeve/