My best tip for any photographer... though I am not a professional... is to go shoot.
The reading is good, but the practice is best. And contrary to what some photographers say: "You don't need school"
School Helps! It's a great place to learn styles and also network with your classmates which will also be photographers who can probably pass you some business. I happen to believe school is important and a certificate is a great tool to show clients that you know what you are doing.
Visit MasterFile Stock Photos. Amazing website people can get inspiration from how to take commercial/corporate pictures.