Before you worry about how to accept payments on your site you need think about shopping cart software. Mals-e is a great free one that can accept all forms of payments if you have the accounts set up. It integrates with option cart and many others. Option cart allows you to create a base template for your website and has an easy to use backend that allows you to add products, categories and inventory easily without coding. It generates the add to cart buttons in mals-e code. Here's an example of a site using option-cart, mals-e with paypal+google checkout. AngelPack ergonomic baby carriers a soft baby carrier for every style
Mals-e: Features - Mal's Ecommerce
Option Cart: OptionCart - ecommerce shopping cart catalog for small and home businesses | 
