Just HOW are you wanting to format the singing? Parts, as in SATB? Most folk music is not formatted for anything except the melody line, and you would probably have to work out other parts yourslef. Is this a condsideration? Finding the correct key for children/adults and male/female ranges may also be a serious consideration.

I would suggest that to begin with, at least, you sing "simple" songs--5 note melodies in EZ keys, such as D, G, and C. Songs like "Children's Songs"--Kemo Kimo, Old Joe Clark, BINGO, etc. I know these are not very exciting songs, but they will get you started.

Then, think about moving "up" to some of the Child Ballads, most of which are still 5 note tunes, but more challenging in terms of key and rhythm. Memorizing the words is more difficult with the ballads, though, it seems. They can be soooooooo long.