Honestly, I think you'd be better off just using a dwarf NPC. Non-outsider hybrid races, like half-elf and half-orc tend to not do anything that the non-human parent race doesn't already do better, and the bonuses they do have over humans usually aren't anything to write home about. Plus I'm not sure dwarves CAN breed with non-dwarves, even if they'd ever choose to do so.
That being said, if you really want to make a half-dwarf,
this could be a good starting point.