I was fortunate to win a copy of the Safeguard Health & Safety Handbook. It explains legislation and references case law. I keep my copy on my desk as a reference. It helps me accurately and clearly advise directors and officers of their responsibilities. The book is collaborative effort by @Mike Cosman, @Ann Butler, @Craig Marriott, Michael Tooma and Rachael Schmidt-McCleave and I believe it is updated annually.
Like others I highly recommend Paper Safe & Challenging the Safety Quo. Another good one is 'Organising for Safety: How structure creates culture' by Andrew Hopkins. I'd also recommend listening to The Safety at Work podcasts by David Provan and Drew Rae. You can find them on LinkedIn (search for The Safety of Work or connect with David).
It may depend on what your primary interests are with respect to informative reading material. Most of the publication referred to in the previous posts relate to legislative interpretation, and influencing human behaviour. There are many publications that refer to the technical aspects of workplace health and safety in relation to identifying, assessing, monitoring and managing hazards. I have several in my library, some dating back to the 1980s, that continue to provide, to this day, useful information on identifying and analysing hazards ranging from how to conduct an occupational hygiene walk-through survey, how to interpret WES's, basic toxicology and epidemiology, the nature of gases and vapours, microbiological hazards, physical agents the workplace (RF radiation & ELF fields, vibration, heat stress, work in cold environments), noise and so on. Occupational Health and Hygiene – Guidebook for the WHSO by David Grantham, and Managing Occupational Health and Safety in Australia by Michael Quinlan and Philip Bohle, are two such examples, both published in 1992. A visit to the public library, or if in a small town, on your next visit to a larger city it would be worthwhile spending some time in the technical section. Identify from there, publications of interest, and follow-up on how to get hold of them.