Chugalug_ :
@OP, for the SSD you want to put OS, and any software you might want on it, e.g. Malwarebytes, Microsoft Office, Steam (put your game directory on the HDD) or otherwise.
The HDD is your storage, the SSD is your software and OS.
Leave at least 40GB spare on the SSD at all times in order to prevent performance drops, and don't put games on it, maybe the one game you want faster loading times in provided size isn't too big, but that's the only benefit it's going to give you.
Thanks a lot, Chug. You've been a big help.