Any furniture store that sells leather will sell a leather cleaning kit. They generally cost about forty dollars but will last for years. In them is a stick (about the size of a glue stick) that will take ink out. It also contains a conditioner and light cleaner. It will make your leather furniture look great and will keep it from drying out. I also use the McGuire's leather wipes (they come in a black pull top bottle like wet ones and are sold in the automotive section of most stores) for a quick clean-up and conditioning.
