I just want to reiterate what others have said. It most important to minimize pressure between the interface of your hands and the bars. So cushioning with gloves and bar tape, road surface etc (Kiwi Stoker lists it well) and bike fit is very important. To the extent that you can get more weight on your bum and off of your hands that's good. Sometimes how that is done is counter intuitive, saddle position fore and aft, tilt and the saddle itself can be very helpful (as well as the usual stem length, handle bar width, using flatter bars). If you can get a good pelvis position on your saddle, combined with good core strength, you should be able to ride with very little pressure through your arms.

Hope that helps.