A little OT: Learning to sing the blues?

Lately I've been working on my accompaniment playing. 'Cuz of this, I've also been trying to sing. I have to say I've been having a hard time. I used to sing in an indie rock band (singing my own tunes and lyrics) and did ok. Now that I haven't sung in quite a while and I am singing blues, I've been having a real hard time sounding anything close to good? Does anyone have any tips or know of any books or videos that might help out? Or should I just practice singing to blues albums?
Thanks!