My suggestion for getting DH involved: When you bring your DH to the store stick to one or two categories and ask him which he would like a say in. For example, he may not care which sheets you register for but might want a say in baby gear. Just ASK him and don't assume :)
And let him know in advance what the goals are. "Today we'll look at the gear you said you were interested in and we'll need to chose a swing, baby carrier and PNP. If you want to continue we can also look at bathing supplies. Or we can be done, ok?"
And def start a registry online; you'll get coupons and free bags later.... And know that it is a process so good for you for getting started early. Good luck!