If you're selling more than 50 items per week on Amazon, you'll need a listing software program that will save you boatloads of time.
Two of the more affordable listing tools are ScanPower (formerly 'FBAPower') and Listtee.com.
I used ScanPower for a year but then switched over to Listtee.com. You get an extended free trial for Listtee if you provide coupon code FBAFINDS at theckout.
Check out my video review/comparison (Time alert: this video is 20+ minutes long.)