Hi R.,
I am 34 & have 3 children. Ages 17, 11, & 5. For the 17 & 11 year old, I had no idea how to get them on a sleep schedule & like your baby, they stayed up late. I couldn't bring myself to leave them crying in bed, so I stayed up & rocked them for hours until they fell asleep. & then when I put them in their crib, they woke up & wanted me again. (Ended up in bed with us!!)
If I had followed the advise of the baby books, I could've saved the family alot of sleepless nights. So, on child #3, I finally did what the professionals advised & the benefits were well worth the few weeks it took to get there.
Step one, (you already seem to have a boy who will go to sleep himself, so this will probably be a blessing.) You have to let the baby cry himself to sleep. So be prepared for some tough moments on your heart-strings..
Step 2, Get into a ruitine of feeding your child his last feeding & then having something like a bath or singing or a radio playing lulubies that will teach your child to calm down & expect to go to bed. (I stood & rocked my baby while singing 3-4 songs.) Make sure your baby is AWAKE when you put him in his crib. Make sure his diaper is fresh, & since you just fed him, he should be good to go.
Step 3, LEAVE the room, (after you kiss & say good night.)
Step 4, if the baby cries wait for 2 minutes before you check on him. Walk in the room, check his diaper, if he's dry, say goodnight & leave the room.
If he continues to cry wait five minutes & walk in, check his diaper or burp him & leave the room.
If you're sure he's not sick, wet, or has a gas bubble, then do not go in the room anymore.
Use a monitor to hear him, & he may cry for 20 minutes the first few weeks before he goes to sleep. That's OK.
Step 5, don't wake him up for night feedings. & if he wakes up crying, don't rush to feed him. Give him 5-10 minutes to see if he'll go back to sleep. (That's the hardest part.)
I breastfed my baby for 6 months, & by the forth month, he went to sleep at 7PM and woke up at 7AM. (One night feeding at 10 or 11PM & right back to sleep.) Plus he took a three hour nap in the afternoon. (using same steps to put him down awake in his crib...) (He was adorable amusing himself & talking to himself in there as he got himself to sleep.) & I think that helped him to learn to entertain himself, because he plays well & is very imaginative with his toys now. He is now 5, robustly healthy & very smart. Early walker & talker. Not to mention loveable & secure, so don't think that doing these steps will damage your baby, (like I did with my fist 2..lol)
Good Luck!! K.