I have an online shop and I would like to begin accepting bitcoins as a payment method. How can i do?
You can use BitPay's existing network or Zen Cart allows you to setup your own node to receive Bitcoin.
Or, alternatively, if you don't want to sign up for a BitPay's merchant account, or because you also want other altcoins, you could use something like Coinpayments,
https://www.coinpayments.net/, which i believe supports over 200 coins.
I've looked into using them myself aswell and it looks pretty promising. Only 0.5% fees on incoming merchant transactions ( i believe Bitpay is 1%?)
Anyway i'll look into Zen cart myself to see what it is aswell, sounds interesting.