Despite what others say, not particularly great for a beginner ...
Without some sort of case to mimic a keyboard chasis/plate to hold them, pressing these won't really give you a proper indication of what it's like to have them on a keyboard.
Having said that though, the pack does give a variety of different types of switches and would be great for someone who maybe already owns a mechanical keyboard with removable switches and didn't do too much research before getting it. Putting these in the arrow key spaces on a TKL might be a good way to test a few at a time.
This set is great, a good price, and as a beginner who is going to build her own keyboard, a nice introduction to switches. But there are no labels! Someone more advanced than me would probably have an easier time knowing which switch is which, but for me, it’s tricky.
I had never built my own keyboard before, so I was unfamiliar with the differences between the switches. This was super helpful in deciding which switches I wanted to put in my board. I'll definitely use it again in the future next time I want to "switch" up my keyboard.