First of all, I would recommend finding a local rocketry club. They will be able to help you especially with the legal FAA stuff. Secondly, when designing your rockets, there is a lot of aerodynamic stuff to consider. Here is a link to free software that you can use to design rockets. Link: http://openrocket.sourceforge.net/ It's geared for smaller rockets but will handle larger ones. My college's rocketry team uses this software, and we built a rocket designed to fly to 25,000 feet. Also, recovery is important. There are a lot of parachute options. Below is a very good paper about recovery systems for large rockets. It may be too much for where you are now but as your designs grow a lot of this information will become very useful. http://www.ricknewlands.webspace.virginmedia.com/downloads/technical-papers/Parachute%20recovery%20system%20design%20for%20large%20rockets.pdf Finally, PLEASE BE CAREFUL!!! These things can be very dangerous. I will reiterate that it is a very good idea to join a club because they will help you stay safe.