Depending on your country’s jurisdiction, the best way to do it is to check with your regulatory bodies on the type of licence to apply for (this is the foundation)

Once approved, work on contacting the digital currencies to apply to be their merchants. That won’t be really tough to do. E-gold/ E-bullion requires you to buy at spot on prices depending on which you’ll be wanting to trade.

Or you can even offer to buy from people and sell it back. It’s just that simple.

Website in my opinion is important, but its a secondary component as apposed to your licencing, contacts and the way that you approach people to use your services.