Yes almost always if it is for your personal reference and you don't impose song sheets and books on others if that is not the culture of the group.

Yes if you have set up the event, circle, camp, party. Do it however you like it and tell people in advance so they can come for the cookies and perhaps the music will not be to their liking but they like the people etc.

No if a group has existed for some time and it is their tradition not to use books. Do not ruin a good ongoing group by imposing group songbooks on them. This has happened all up and down the west coast of USA like a terrible virus and the good groups are pretty much gone except at private functions, which you and I might never hear about. I am talking not about using a book for your own personal reference but the practice (and I won't go to these places if I know in advance) of taking out the blue book and going to some song and telling everyone the page number and suffering through it, although others could enjoy it. mg