I would recommend against suggesting to your friends that they should switch to a Linux-based operating system. The benefits aren’t immediately obvious, and if they’re already used to using Windows or Mac, they will likely find Linux to be restrictive, difficult to use, and buggy. As someone who’s been a full-time Linux user for over 15 years I’ve seen it over and over again. It’s a big jump, and TBH free graphical applications are much more rough around the edges than their commercial counterparts. Most people who try it will not be happy, and will likely tell others that it’s no good.
Instead, what I do, is to promote free software that people can run in their operating system of choice. Maybe, after a few years of chipping away most of their non-free software stack they might be interested in giving it a go. Maybe they’ll want to setup a server, or play around with an embedded system – and they’ll know who to turn to for advice.
They’ll know free software tends to need a little more massaging to get it to work, but will have worked out the benefits outweigh the occasional hiccup here-and-there They’ll be familiar with some of the software options and won’t get so overwhelmed on day one. They’ll already know what kind of user errors cause problems, and won’t compound the inevitable issues they’ll run into by not making as many “dumb” mistakes.
I put my energy into selling the ideology of free software, not the software itself. We should be able to examine and hack our computers. There’s no reason we shouldn’t be able to lend a hand improving the software we use every day – whether it’s coding, re-writing a poorly written sentence in the documentation, helping with artwork, or even just showing others how you fixed a PEBCAK issue.
Most people won’t be as interested in in this as you and I, so warm them up slowly and do your best to make good suggestions.
There is one major exception to what i’ve said here – technologically impaired boomers. Unless they’ve been using computers all their lives, every computer is a confusing mess to them. Also, most of them love not having to pay money for something that you usually have to pay for. Set them up with Ubuntu and be prepared to serve as tech support for quite a while…
Hope my 2¢ helps!