Q: I'm stuck on "Waiting for changes to be applied"

Hi, K Harris.  

Thank you for visiting Apple Support Communities. 

There could be multiple causes for this issue and I will do my best to provide a couple solutions.  I would recommend starting with going through the two articles below. 

iTunes: Resolve USB-related alerts

http://support.apple.com/kb/TS5254

Resolve issues between iTunes and security software

http://support.apple.com/kb/TS3125

Cheers,

Jason H.