Handgunlaw dot US is the most up to date and carefully double checked resource .
*****This is what we generally steer folks that have questions regarding a variety of handgun related law issues to. It's a decent site. In addition, we recommend the MSP website (MD State Police) as well, for Maryland related questions regarding this issue. Laws change, and not every instructor can know everything, or be 100% current for the most part. Mistakes absolutely happen, and I have taken classes where information was either incomplete, or perhaps a bit out of date - it happens for sure.
However, you would be surprised at how often the opposite happens where a student heard something at the range or a gun store employee told them, or their dad/grand-dad who is a Vet but not that kind of Vet and doesn't take care of pets, etc... tells them something that is so off the wall crazy they have to be corrected lest others wonder if the info is correct. IME, it is usually related to transport and carry to and from the range, magazine size possession versus use, CCW into a business, amusement park, bar, church, etc.. The purchase of handguns through dealer vs face to face, gun show loopholes (CNN said so!!!! ), etc.. We have copies of relevant as of the time of the class law and general guidelines but always tell folks laws DO change so one needs to be cognizant of these changes.
Anyway, lots of examples of bad info, and Maryland handgun laws are generally NOT written to favor the gun owner. Things would be so much simpler if we cut out a lot of the laws related to carry, transport, etc.. and just wrote something like... uhhh... this..