Q: iTunes on my PC and MAC

I have my iTunes on my Mac at work but all of my other devises (Mac, 2 iPads, 2 iPhones, 2 MacBooks) are Apples.  How can I sync my iTunes so that when I purchase something on iTunes it is automatically sent from my PC (where is it bought) to all of my other devices?  Sorry, I this is probably very simple for most of you on this forum, but I want to know the correct way to do this before I make more trouble for myself.  Thanks for any and all help.