My lady has a 'Youth Hosteller's Songbook' which has many of the sort of songs that at least scouts and guides sing.
As far as I can remember, and as Doug Chadwick implies, it is an oral transmission process. Local scoutmasters here have printed out some of the words, and some of the sketches that cubs and scouts do, but I've never seen an official songbook. I'd like to, though. Perhaps a Mudcat project? There should, perhaps, be American and English versions, because although there is a large overlap, I noticed on previous threads that there are differences.