Before starting to make any fireworks yourself, you should take the time to read these two articles. Both of them could save your life, and prevent catastrophic accidents which could kill or injure those around you. Keep in mind that accidents in fireworks making usually happen so fast that you will have no time to react. Unlike all the other accidents and near-misses you have had in your life, pyrotechnic reactions are so fast that you probably will not be able to escape in time. Read these articles. Save your life, and the lives of those around you.
Fireworks Safety 101 by Kyle Kepley, intro by Ned Gorski
Fireworks Safety Manual, a collection of essays by Bill Ofca