Making a Rocket

Hi.
Has anyone ever been working on Rocket? We created a Team to join a contest in Turkey.And want to make Rocket (we want to make with arduino).We are working on it. So if anyone has an experience about making a rocket, I want to ask some questions.

How should we start to design? or What are steps to be successfull (or make)

What kind of materials should we use?
What are your advices ? (of course you can give advice about other topics)
I’m waiting your answers.Have a good day!.

First of all, we want to make

Short (5000 ft = 1.525 km approx.) or
Medium range rocket (10000 ft =3.050km approx. ). (With at least 4kg mass)
Our questions are :

How did you start to Process planning?

Do you have any extra sources to help us ? (Article, website, etc.)

Which sources did you use it while making it? (We have some sources of course but extra information might be good for everybody as you know.)

Which Softwares did you use? (For design, simulation , calculations etc. )

Do you have any advices for us while making rocket like “You MUST do this,that while making or designing.This or that part is reaaaaly important!!1”

And what kind of team you were and what kind of rocket did you make?

For information:

Like I said before, of course we have some sources, softwares etc. I asked these questions for extra data.
Now, whole team members are doing research and gathering new informations.