Our parish has just bought a new set of hymn books. I was horrified when I saw what was in them, but apparently the edition is the best available, which is worrying. They are full of all the tired old folksy stuff from the late 1960s, though the decent music is there as well, but you have to look for it. The Taize chants are quite pleasant and fine as an introduction to both Latin and part-music, do not amount to much. Also of concern is that what Gregorian chant was in them was written out on a five line stave instead of the proper four-line notation.
The latter point is not a matter of pedantry. It is easier for beginners to read the Gregorian four line notation then music written on five lines simply because it has one less line to pick the notes out from. The Gregorian notation also leaves the words intact so they can still be read, instead of breaking them up with huge spaces in between. More importantly, there are features of Gregorian chant which just cannot be recorded in modern notation. One of the reasons why Gregorian Chant has a reputation for being boring is that performers have been reading from five line staves and the subtleties and detail are ironed out.
The main elements of singing from the correct Gregorian notation can be learned in about half an hour, and it is well within the abilities of the average ten-year-old for whom "Plainchant for Schools" was produced. A good Gregorian music book for congregations is Liber Cantualis, which costs a bit more than the average hymn book but solidly bound and made to last.
There has been a succession of documents from Rome reminding clergy that congregations should be familiar with the simpler Gregorian Chants and it is sad when the clergy lack the will to carry this through.