Sleep Schedule

My son will be 3 weeks old this Thursday and I go back to work 4 short weeks. I'm wanting to try and get him on a sleeping schedule (although with him being this young I don't know if that's possible.) Any advice on how to start this? What did you other moms do to help your baby get to sleep at the same time every night and what helped them stay asleep? We do co sleep. BEFORE ANY JUDGEMENT HE IS IN A CO SLEEPING BASSINET, HE IS SAFE AND NOT ACTUALLY LAYING IN THE BED.