Reddit reviews The Empire of the Steppes: A History of Central Asia

I would recommend Rene Groussets The Empire of the Steppes: A History of Central Asia, its quite dated but overall still the go to source for a complete history of the Steppes various Khanates etc. There are several chapters about the Gokturks alone.

https://www.amazon.de/Empire-Steppes-History-Central-Asia/dp/0813513049

• David Christian’s A History of Russia, Central Asia and Mongolia is a good general overview
  
  
• René Grousset’s The Empire of the Steppes is a bit outdated, but perhaps more readable—more in the style of Gibbon
  
  
• John E. Hill’s Through the Jade Gate to Rome is a fantastic translation and analysis of late Han Dynasty reports on ancient Central Asia
  
  
• Jack Weatherford’s Genghis Khan and the Making of the Modern World is a great history of the early Mongol Empire
  
  
• Hans-Joachim Klimkeit’s Gnosis on the Silk Road is a fascinating collection of Persian, Sogdian, and Uighur Manichaean sources
  
  
• The Palgrave Concise Historical Atlas of Central Asia is disappointingly sparse, and a bit odd in its coverage and terminology, but it’s still the best I’ve been able to find in the style of Colin McEvedy’s Western Civ atlases

The Turks In World History by Carter Findley would be a good starting point, as it covers Turkish history from Steppes to the present day in an accessible manner. It's a broad approach, but should be able to give you a framework to discover topics you may want to explore in more depth.

Since the Turks are a Central Asian people, you may want to learn more about Central Asian history in general. Grousset's The Empire of the Steppes: A History of Central Asia is the authoritative tome, but be forewarned, it's dense, really dense.

This is a classic for sure, but it's a bit expensive bought new: http://www.amazon.com/Empire-Steppes-History-Central-Asia/dp/0813513049/ref=pd_sim_sbs_14_5?ie=UTF8&dpID=51knWPD2HSL&dpSrc=sims&preST=_AC_UL160_SR104%2C160_&refRID=04WY3HDVNEBNV6HBWVVK

In addition to a chapter on Timur and the Timurids, there's a huge amount of other information on the related peoples.