Note: Not all fake books or real books have the same format, most will have sheet music with chords marked, some also have lyrics, a few have tablature, they are sometimes also available in different keys and arrangements to suit different instruments.
For an excellent collection of fakebooks to buy, checkout www.sheetmusicplus.com, who have a selection of some 1200+ to chose from, they also have good search facilities AND include content indexes for their books.
O Could I Speak The Matchless Worth
O Day Of Rest And Gladness
O Del Mio Amato Ben composed by Stephano Donaudy
O Divine Redeemer (Repentir) composed by Charles Gounod