Just thought I'd share this chart (linky below, chart found further down the page) I found today. It shows how much long a baby can normally nap, and how long they usually stay asleep for naps along with some other helpful info.
Even as a STM I feel like I've forgotten a lot of what to expect for these first few months. It goes so fast, and their habits change often! Hope this site can help some of you a little. I felt a lot better seeing that at 6 weeks a baby may nap anywhere from 30 minutes to 2 hours. So when he wakes up after a short nap, I don't need to waste my energy trying to put him back to sleep. That's normal, and may be all he needed!