Hey there, stobbsie.
If you want to transfer already installed programs from your SSD to the HDD, I'd suggest that you uninstall them first and then just reinstall them on the HDD so that you're sure that there won't be any problems later. As for transferring files like picture, videos, documents, etc. I'd recommend that you copy them over to the HDD in newly created folders (I'm really not a big fan of relocating Windows' User Folders). From then on you can just set all the default save/download location paths of your programs and browsers, to your HDD.
Anyway, if you do decide that you want to relocate the user folders, just look it up on Microsoft's website as I don't know which version of Windows you are using and can't give you a link for the tutorial.
Hope that helps. Please let me know how everything goes.
Boogieman_WD