The tylenol they had me take after Kyan was born and for a few days afterwards was Tylenol 3 (prescription only) that had codine in it. I breastfed and the only thing I can say was that he slept well too.

I totally didn't think about it at the time but assumed it was okay since they knew I was exclusively breastfeeding and gave it to me anyways. I'd check with a Dr. though.
I second not co-sleeping and also making sure that your dh is fully able to listen for the baby and everything. That stuff can really knock you on your ass if you're not used to it.