How do I get my mp3s from my hard drive to my speakers?

So I can get a tablet with good storage, stuff it with MP3s and put a Jriver or equivalent program and right now stream to the Sprout via Bluetooth as I do with Pandora. and then when I upgrade away from the Sprout, just make sure I have a Blue toothable device hooked to the Freya +.
Or am I totally wrong? 

So I can load the files on a tablet etc and USB them to the DAC.
I want to stay very far away from the Apple universe. And at this point not interested in streaming. I have been running thumb drives to my receiver in my cars for many years.