you need to get a merchant id from the bank your business will be using. I dont know how much that is but i think its expensive, - for a start up anyway.
Online selling- Monthly costs circa 60 euro a month and no transaction fee if under 100 transactions a month not much a transaction after that
Over the phone you still need a merchant id and a card terminal.
Best bet is to contact your bank and see a new business person, contact an online authoriser such as Realex ,contact the enterprise board , they have a good information booklet on starting up and selling online.( all the legal stuff,eu law etc, )
The bank and the authoriser company will need to see the site before they allow you to use them
Any queries, pm me i went through this a few months ago
I am also trying to receive money by credit card payments over internet too. I e-mailed an Irish company Realex giving my telephone number and the company phoned me almost immediately... great service. gerard.hanratty@realexpayments.com