I only do abs twice a week Mon and Thur. just crunches and hanging leg raises about 3 sets each 30 reps. As far as weight ill only throw in weight once in awhile like 35 pounds max. You dont want your abs to be huge because then it will look like you have a gut. Keep your abs in high rep. If your abs can be seen and you have a low body fat I would use 0 weight. I have deep definition in mine so I train just to keep them cut mostly.
