This review from Chest belongs in your list of references. You’ll find out how the latest evidence applies to questions such as these:
What tests are indicated when?
What is the role of the gaps (osmolar, anion and oxygen saturation) in establishing a diagnosis?
What is the role of GI decontamination?
When does the Rumack-Matthew nomogram fail to identify patients with acetaminophen toxicity in need of treatment with N-acetylcysteine?
What are the indications for hemodialysis?