I want to first say, DO NOT NOT NOT put cereal in his bottle!!!! This is SO bad for him!!! Ask your Pediatrician, I can guarentee they will forbid this.
I just got my daughter on a great routine (thanks to alot of parents on here giving great advice!)
So, I am going to pass on what helped for us-
We eat dinner every night between 6and 7pm. If you are giving him cereal WITH A SPOON I would do it while you eat dinner, so he can be at the table with you (this is very important to my family).
After dinner I let my daughter play until 8pm. Of course if you want bedtime earlier you can push everything forward! At 8pm we go upstairs, take a nice warm bath, go to her room, where there is only a dim light on, and get ready for bed. This includes a rubdown with lotion, diaper, and PJs. After she is all ready for bed we read a book or two, and then I nurse her for 30 min. I know some people dont think you should use bottle feeding or nursing as a way to help them sleep, but I do :) By now it is about 9:30. I stop her from nursing, lay her in her crib, and rub her back. She falls right to sleep!!
We have been doing this for a week with great results!!
Of course this will only help get him to sleep. It wont help with him waking up. Does he still wake for nightly feedings? If so, then when he wakes up I would feed him in his dark room- dont take him to another room, change his diaper (unless of course he stinks!), make the bottle and all that, that will get him all woke up! I would go get the bottle when you hear him(or if you are nursing you are good to go!) go in his room, pick him up, feed him, and put him back down. Dont talk to him too much. This should help him fall right back to sleep.
Good luck!!