Your newborn should breastfeed at least 8 times a day (24 hours). When he's nursing you should be able to hear lots of swallows--about 1 per second after the first few days of life. They will sound like a soft "kuh." When he's finished drinking, a satisfied baby will look very relaxed and satisfied--kind of like he's drunk. He will likely fall asleep.
Another indicator your baby getting plenty to eat is his diaper count. What goes in, must come out! He should have at least 5 soaked diapers each day and at least 2 big poops after day 4. Most breastfed babies stool with each feeding--that is normal and desirable.
If you have any doubts that your baby is not getting adequate nutrition, contact your pediatrician or lactation consultant as soon as possible.
I have written an article on this topic for my blog. Here is the link. http://wp.me/pEZ6A-1J