User blog comment:Hatebunny/On the cancellation of Hellblazer/@comment-27647819-20160513022116/@comment-3361105-20160513161522

Pretty much is the place to start. Once you're familiar with the character from that, you can pretty much pick and choose.

Some required reading (as far as I'm concerned):
 * Hellblazer: Original Sins
 * Hellblazer: The Devil You Know
 * Hellblazer: The Fear Machine
 * Hellblazer: Dangerous Habits
 * Hellblazer: Fear and Loathing

preferably, in that order.