When DD was first born, I was scared to keep her awake after nursing because getting her to nap/fall asleep was a nightmare. But the rewards are huge! It'll take some time and patience but it will pay off. Now I have a baby girl that goes down without any fuss. As far as nighttime feedings, it's okay to let him fall asleep during nursing and to put him back to bed asleep, no need for activity. Just make sure he gets in a good feed and doesn't fall asleep on you with a half-full tummy or he'll be up again. This young age is such a struggle for them to stay awake while eating, my DH used to laugh at me all the time as I'd try to keep DD awake.
As far as a wind down, this is what I did when my DD was that age: after feeding and diaper change, I would sit with her and rock her in her darkened room and hum or sing to her until she was very dreamy eyed and almost alseep, then I'd lay her in her crib. Gradually I worked toward putting her down more and more awake. It took a lot of time for her to work to independent sleep, but whatever little steps you can do now will make a big difference.