While this website only covers US rules, I have never seen any significant discrepancy between US and other countries, so this is good starting point for international travel as well
Be prepared for inconsistencies. I've had security officers remove items that were clearly allowed. I also got through with items that were clearly not allowed. Just go with flow and don't argue (it won't help). Just let them toss the item and buy a new one (unless it's something valuable).
Every check point has somewhat different rules: what has to come out of bag, liquids, shoes, belt, jackets, etc. Just look around and see what other people are doing and who gets yelled at.
If you travel with somewhat unusual items, you can choose to take them out proactively. In my case this has been Rubik's Cubes (no idea why) and a measurement microphone (which is a longish metal object).
Be prepared for inconsistencies: I have been yelled for not taking stuff out and I have been yelled at for taking stuff out. Just ignore it.
Occasionally you may find the label "SSSS" on your boarding pass. Congratulations: you have won the lottery for "Secondary Security Screening Selection", i.e. you will be pulled out for a separate manual screening. Head to security a bit earlier and make sure you carry-on is squeaky clean.