Q: how to sync my iTunes from my desktop with my lap top

Hello, hathewayc.  

Thank you for visiting Apple Support Communities.  

I need clarification on your question to provide a better answer.  However, if you are wanting to sync your iPod with multiple iTunes libraries see the article below.  

Manage content manually on your iPhone, iPad, and iPod

If you are wanting to combine your iTunes libraries, here is an article that will help you with that scenario.  

How to move your iTunes library to a new computer

Cheers, 

Jason H.