Reddit mentions of Techniques of the Contemporary Composer

Can't speak on the exercises you seek, but best composition book I've ever come across is David Cope's Techniques of the Contemporary Composer.

Might have to dig around the web for an affordable copy, though.

I like Cope's - Techniques of the Contemporary Composer.

Some of it is a little outdated. I think score study of works you really like is what will be the most fruitful.

Here's some other stuff for people interested:

Joe Straus' Introduction to Post Tonal Theory

• For solid post tonal and heavily set theory based stuff
  
  Introduction to Electro-Acoustic Music by Barry Schrader
  
  
• this book is old but has some cool stuff in it about earlier electronic music and it's cheap
  
  Samuel Solomon's How to Write for Percussion
  
  
• The best percussion book
  
  Rothenberg and Ulvaeus' Book of Music and Nature
  
  
• If you're in to, well music and nature this is a great anthology of writings by people like Cage, Takemitsu, Oliveros, etc. on the subject.
  
  Cope's Techniques of the Contemporary Composer is okay.
  
  
• for composery stuff
  
  My favorite orchestration book is actually the Blatter
  
  Composing Electronic Music by Curtis Roads is a very good new electronic book
  
  The Rest is Noise by Alex Ross
  
  
• Practically a must read
  
  On Sonic Art by Trevor Wishart
  
  
• is a must read also

This is a good, basic book, which covers just about everything. Techniques of the Contemporary Composer-

http://www.amazon.com/Techniques-Contemporary-Composer-David-Cope/dp/0028647378