Singled out for good by Paige Benton Brown
"Let's face it: singleness is not an inherently inferior state of affairs. If it were, heaven would be inferior to this world for the majority of Christians."We're Not on Hold: Biblical Femininity for Single Women by Carolyn McCulley - audio recording from the 2004 Desiring God National Conference.
For Single Men and Women (and the rest of us) by John Piper
Do you have any?