Find online a baby checklist, that's what I did (I found one on pinterest).
Pack n play, maybe a swing or a bouncer chair, baby monitor, car seat, stroller, bathing supplies high chair & maybe a couple clothing items (:
I would try to find a checklist and also I went to the baby section online and went through each department, takes a little longer but you don't miss anything that way.
Diapers and wipes! You never can have too many of those!
Wal-Mart has a registry and on there is a check list that I found helpful
Don't forget to add those little kits to clip there nails and stuff like that and I added little remedies for baby just in case he gets sick I have it ready .also diaper bag
I did a registry on Amazon.com and they take you through all the different baby supplies and you pick what you want to add.
Not sire if i could live without: diaper genie.. Personally I did one of those baby check lists from online (google search, new mom checklist) and went to myregistry.com so I can put things from ALL different retailers on it, no limits, good luck.