Recently i was having some problems with iTunes 12 on Yosemite and iTunes wouldn't respond after a while or iTunes would just crash when playing a podcast or search the iTunes store.
But there is a simple fix via the terminal following this kb article from Apple for resetting the Sync services :
Fix from apple: http://support.apple.com/en-us/TS1627
OS X Mavericks 10.9.3 and Later defaults delete com.apple.SyncServer SyncServicesResetWorldRunOnce