I follow the 'awake' times found in the Baby Sense & Sleep Sense books. (for B's age its 2 hours) As a newborn I stuck to the awake times religiously till I figured out what her queues were for a nap.
Possibly the most important thing with a newborn is to establish a clear difference between day and night. We started from day 1 and never had a problem with B mixing up the two. Tips for this: Days should be light, nights dark. Keep lights at night to a minimum. Noise during the day (tv, radio, dryer) quiet and calm in the evening. Have a bedtime routine that's predictable. During night feeds keep interaction to a minimum, no playing, chatting or bright lights. When baby gets up in the morning (at a decent hour!) greet him/her, chat and play a bit.
All babies go through growth spurts and during the early weeks I would suggest feeding on demand whether breast or bottle. Personally I wouldn't start sleep training before 6 months.