I'm using The Complete Idiot's Guide to Playing the Fiddle. It covers the basic's of fiddle playing, and has chapters on the Scottish, Irish, Old-Time, and Bluegrass styles, followed by chapters on more advanced techniques, playing up the neck, and playing faster. The empahsis is on learning to play by ear, although the basics of reading music are covered. All the sheet music includes fingering notation, and fingerboard charts of the proper key appear with the printed music for each tune, but they are a little small for me to see while playing. The book comes with a DVD (that plays on my DVD player, but not on my laptop's DVD player) that has some basic video lessons along with audio tracks of all the tunes included in the book. I'm only just beginning, but it seems like a good, basic book on learning to play the fiddle. It's a little light on exercises, but has 80+ tunes. I like having an audio of how the tune should sound, but I would have preferred a format other than DVD. 

If you're looking for something more advanced, that covers more fiddle styles, and provides a more in-depth breakdown of the techniques used in each style, look at The Fiddle Handbook. It assumes you have the basics down pat, and focuses on the history of each style, and what makes each style unique. The book is heavy on fingering and bowing exercises, and has only a few tunes in each style. The fiddle styles covered are Irish, Scottish, English, Klezmer, Eastern European, Old-time, Cajun, Bluegrass, Western Swing, Country, Blues, Rock, and Jazz. All the exercises and tunes are included on 2 audio CDs that come with the book.

Neither of these books focus solely on the Old-Time fiddle style, though, so they may not be what you're looking for.

Mike