Here in Canada and in many U.S. states waivers are a proven means of defending claims of negligence. We also know that poorly 'delivering' the waiver can erode or eliminate its validity. Two students in my Risk Management class at Algonquin College Outdoor Adventure guide training diploma came up with this great visual to map the waiver delivery process. Make sure your org ticks all these boxes! Thanks to Samantha Foster and David Magee for this.
As an aside, little known fact: the 'keep for 7 years' is not grounded in any law. In my jurisdiction, the statute of limitations for personal injury is 2 years (and for most claims). There are a few exceptions, which is why we round it up. If you know where the number 7 came from (or have a good guess), I would like to hear from you! It somehow has become the defacto belief that that is the statute of limitations, which is incorrect.
See also a previous post on waiver delivery here.