Welcome to the Dis Boards!!
There is a list of abbreviations used on the DisBoards that can help you familiarize yourself! I still cannot remember them all!
To find out if the Dining Plan makes sense-go on over to the Disney Restaurant section & there is a Disney Dining section & posted on the top of the page, there are 3 posts (stickies) that stay there & they break down the prices of the dining plan & what's included & how much it is to upgrade. Very helpful!!
Also, on the top of this Board, you can find Codes & Discounts (I think it's called-lol..habit to just look there) & they can break down the discounts available-if any! There is a certain time period that discounts come out (they also tell you what past discounts have been) & you can book a package now & what many people do, is the day that the promotion goes live, you call (as soon as the phone lines open-lol) to have that discount applied to your reservation if possible. There are only a certain # of room categories available for the discount.
AAA can also save you a % if there are no discounts. Sometimes you save enough $$ for food, extras, etc. some ppl save enough to feel its worth it to upgrade to a moderate resort.
One more thing about the dining plan-if you're going to be eating all of your meals in Disney, the
DDP can be helpful to pay ahead/budget your food. Disney can be expensive for dining. It's a personal preference.price comparison is good!
You can book a trip with Disney travel co. & just pay a $200 deposit & the rest is due (I think 45 days before-I forget now! Lol)
The value resorts are really great with theming-Sports for the sports lover, etc. Kids love them!!
Not sure when your going in May, but there is also crowd trends you can find on many websites.
To find your post, sometimes it's helpful to subscribe to the thread-I use my phone, so I'm not positive where it is, but it's helpful if you've posted on other threads (postings) I personally think you can book your own trip with the help of these wonderful Dis ppl. They know so much about Disney & everyone is usually very helpful!!
If you want to respond to someone's specific post-you can quote them & then you type your response underneath.
Sorry, I'm just trying to think of things I didn't know when I was new here. It takes practice.
One more suggestion-enjoy your time @ Disney. It's very easy to make your days too long to try & see everything! My kids are older, but we still try & go to the parks as soon as they open to get on the rides we want. We eat lunch & then go back to the hotel for a swim or even a nap

Then, we go out for dinner & some last attractions (we usually eat in Epcot) it's fun to eat at the different countries (Every place usually has a kids menu)
Don't forget the parades & fireworks!
I think for a first trip, it's easiest to stay in Disney if you can. The roads can be confusing & parking.the buses are great transportation. To get the Disney "feel" is just amazing to stay onsite!
Best of Luck!! Hope you & your family enjoy your first trip with your son to Disney!! Once you go, you'll want to go back!!