The characters in Bosch novels can be grouped into different categories. The protagonists, like Bosch, are often flawed heroes. They have personal demons but are committed to their jobs. The antagonists, on the other hand, are not always obvious. Some of them may seem ordinary at first but are revealed to be deeply involved in criminal activities. There are also the characters on the periphery, such as the witnesses. Their accounts and how they interact with the main characters play crucial roles in the development of the plot.
One of the highly regarded Bosch novels is 'The Black Echo' by Michael Connelly. It's a great start to the series, introducing the complex character of Harry Bosch and his detective work in a very engaging way.
I'm not aware of a ready-made list. But you could check out book review blogs or author's official websites. Sometimes, they have such compilations or references for fans.
The order is significant because it shows the growth of the character. Early on, we see a more rough - edged Bosch. As the novels progress in order, he becomes more complex.
'The Drop' is a great Harry Bosch novel. It shows Bosch dealing with a cold case. The story is filled with suspense as he digs deeper into the past to find the truth. His tenacity and the way he navigates through the case makes it a must - read.