I agree with the aforementioned advice. However it is my belief there is more than one way to achieve your goal. The first step is to consider what you see as a total system budget once completed. Do you have an estimate of this? The answers to the questions posed by reubent would prove helpful.
what to buy first
If I am buying from scratch and cannot afford to buy an entire system at once. What should be purchased first? Speakers, Amp/Pre-amp, etc?? Currently I have music with an inexpensive home theater receiver and small B&W speakers. I have music but I will be replacing those items and putting them in another room.