Welcome Matthew and Matthew's son! Definitely get the little man started on rocketry early, and supply all the rockets and motors that you can. It's a great way to stretch his mind, much better than playing video games.
A few tidbits that you may already be familiar with. Blue text is a clickable link.
One of my favorite online stores is
Balsa Machining. Bill has a huge selection of body tubes, nose cones, centering rings, balsa fin stock and blocks, etc. for the scratch-builder. His prices for motors are very competitive. And he has one of the lowest-priced mid-power kits available---the 3" 29mm 'School Rocket'. It can even fly on low-end H motors, should you wish to get into high-power rocketry.
AC Supply sells discounted Estes kits and motors. Great service.
JimZ's site has plans/instructions for most kits that Estes, Centuri et al have ever made, as well as "Design of the Month" rocket plans and many others.
OpenRocket is a free and fun program for designing rockets, testing for stability, estimating altitude, scaling up or down, etc.
Here is a list of some OR files for both older and current rockets. You can print a list of parts needed, templates for fins, transitions, nose cones, etc.
Take your fella to a club launch if at all possible. I guarantee you'll both be excited, and you'll learn more about practical rocketry than you'd get from all day of reading and watching videos.
Rocketry is a bug that bites deep and rarely lets go.
It bit me around 1965..... you have been warned.
Best,
Terry
