Since Apple devices (iPads, iPhones, iEtc) aren't TRL-specific products, I won't be writing directions on how to use them. What I will do is link you to some materials which I've found helpful on how to get the most out of them.
It seems like every day I meet a larger number of people who strictly use their smartphone to get work done, send emails, listen to music, store photos, and the list goes on and on. Smartphones are the Swiss Army knives of modern day electronics. The iPhone is by far the most popular of smartphones, and if you need to know more about it you can read up on it using the iPhone User Guide, or you can watch this short video on the basics of the iPhone.
More and more people seem to be parting ways with their desktop PCs and purchasing tablets. Tablets are much more approachable due to their simplistic design and portability. People also just feel more comfortable using something that lets you interact with it by just touching icons. Since Apple has such good customer service, they have uploaded a searchable iPad manual on their website where you can learn more about how to run it! Also, I've attached a video on some iPad basics that you can look at to get some general knowledge.