@EdRick - You can definitely do it! It is easier once the baby is past the "explosive" stage, but you can hike even sooner. (You just need to bring multiple extra diapers and lots of wipes in case of blowout. It's fortunate that your son is old enough to carry his own supplies now.)
Remember that you will need to bring probably twice as much water for your wife as you used to now that she is breastfeeding! Once baby starts eating solid foods, those lightweight single-serve pouches of fruit, yogurt, etc. make great hiking lunches. (I like the Earth's Best myself.)
But the main thing you need for hiking with a baby is a good carrier. A lot of people use frame backpacks, but these are only for infants older than six months and they are not necessarily the most comfortable option. I prefer a soft structured carrier, like an Ergo. These can be worn on the front for a baby from one month and up, or on the back from about four or five months. Baby is held closer to your body and in a more natural position. Some SSCs have pockets for extra gear, but I find it easier to have one person carry the stuff, and the other person carries the baby. Happy hiking!