Answer these questions.
What is my budget? How much am I willing to spend?
Who will be listening to these? Just you? Your wife? Your friends?
How loud will you listen? Do you like to crank it for Mahler? Or would you like to keep things quiet for Brahms?
How big is the room and how far from the speakers will you be?
A more advanced question would be - what flavor do I like? Warmth? Easy listening? or Intense and dynamic?

If this is you first start up don't bother with tubes or even vinyl unless you have a patient dealer or some experience.
I would recommend focusing on an amp/speaker combination - these tend to make the most difference in the sound. I would also recommend buying a cd player so you can start accumulating physical media and have a great sound.
I don't recommend external DACs or Computers yet - they tend to be a pain and don't often perform well with out hours of tweaking.
Get back to me with some answers,
Sam