Pen and a small notebook! After two sleepness nights (one in labour and the other with a clusterfeeding newborn) my brain was mush. I asked a visiting friend to bring me something to write on and I recorded all of the instructions I was given. Everything from bathing tips to Tylenol timing so I didn't even need to try and remember. Really came in handy later and I'd highly recommend it! Also, baby wipes as I really hated the hospital supplied ones!