The Alex Cross novels start with 'Along Came a Spider'. Then comes 'Kiss the Girls'. After that, there are many others like 'Jack & Jill' which continues to follow Cross's adventures in solving crimes and dealing with the villains in his typical style. Each novel builds on the previous one in terms of character growth and the overarching storylines in the series.
You can check the official James Patterson website. It usually has a section dedicated to the Alex Cross series in the correct order. Another option is to look at book review sites like Goodreads. Often, fans there will list the novels in the proper chronological sequence.
Some of the novels that have Alex Cross as a character include 'Cat & Mouse' and 'Pop Goes the Weasel'. They're part of a popular series that has gained a lot of fans over the years.