First, realize that we all have a roughly-24-hour internal clock and for the last nine months junior has been lulled to sleep as Mom was up moving around and was more alert when she was still. This will take a while to re-phase.

Second, don't make the mistake of being overly-attentive at night. Babies often fuss or want attention or (as they get older) just seem to want to play. Start getting the idea across that nighttime is for sleep. Feed him, burp him, change his diaper, and put him back to bed. Be business-like about it; this isn't the time to play peekaboo. Before long, you will be able to distinguish between the cries that need immediate attention and those that don't. It may sound cruel but sometimes letting them fuss for five minutes, then fall back asleep, is just what they need. If they aren't hungry or wet or feverish, let them fuss even longer.