Joshua you are starting your son's life off correctly by taking him to Walt Disney World for the first time while his age is still measured in months. Awesome parents!
When you first arrive, go crazy buying him cute little Disney outfits. Have you seen how adorable Mickey covered baby shoes are? Now that shopping for tiny, adorable clothes is out of your system you are ready to go.
At restaurants, your baby may eat off your plate. This works best at buffets. Do bring snacks and bottles with your son for meals when you and your wife order food that is not baby appropriate.
Consider bringing your own stroller since the ones for rent in the parks do not recline. At 8 months you will want him to do some napping while you walk around the parks. Just be prepared to fold it up on the buses.
Baby Care Centers are located in each park. These quiet places are a great place to nurse, change your baby, or just take a break.
Plenty of attractions are easy to take a baby on. He can sit on your lap on most any ride that does not have a height requirement. Our babies loved The Many Adventures of Winnie the Pooh and 'it's a small world".
Snap a picture of your little one with one of the characters. You will want this when he goes to college.
Take a break in the afternoon back at your resort. We still do this and my children are all school age.
Please contact me if you have additional questions. I have four children and have brought babies as young as eight weeks to WDW and would love to help you. Enjoy the first of many magical vacations with your new addition!