Are you talking about sheet music? Does he want to start playing again? Do you have any idea what his ability level is/was? Do you know what typeof music played before? (Rock, folk, jazz, ethnic tunes, classical…)
I'd go to a decent music store, the type that sells/rents instruments and hires teachers to give lessons. I'd give some info on your husband's ability (how long since he played, how many years he played before he stopped, what sort of formal instruction he had, what his musical tastes are/were, etc.). Ask for a recommendation on a songbook or two with some assorted tunes at his level and in the type of genre he was most familiar with or most interested in. Ask if the music can be exchanged by him if he wants a different style - be careful with that because some people are unethical and photocopy music illegally and then return it just for a refund. A small, family-run music store will probably be more helpful than a large place geared to serious musicians and large orders for bands, orchestras, etc.
Also, most large libraries have a big sheet music department and you could borrow a few books in the short run to see what interests him. Don't photocopy them but see if anything inspires him to start strumming a few chords!
You could also take his guitar in for a "check-up" to see if it needs new strings or any other maintenance.
