Reply to How to Sell your music via Digital Distributors ?

Greetings

I've started a Record Label, and got 3 artists already signed, but we need more exposure.

2 Artists do House Music and other R&B.

1. I would like to know how I can put my label on online store with our music !
2. I would like to know how I can see music through a reliable Digital Distributor
3. How I can sell/promote my music on Traxsource + Juno + Beatport + iTunes etc etc


I've came across with TuneCore but I would like something very reliable to do it.

Thanks in advance