Participate. Partners of a pregnant woman are entering a major period of transition too- but without the physical aspects to keep them involved, it is important to include your partner in as many provider visits as possible- especially for ultrasounds and planning with your doc/midwife. Childbirth prep class is an outstanding opportunity to learn in an non-judgemental environment.
Planning. Allow them to pick out patterns, colors, planning the room and design. Give them some choices as well.