For Credit card processors, go to the add-ons link in the menu of this website, which is here http://www.drupalcommerce.org/contrib then at the top select from the select box filter by module type, choose payment. You will then see credit card processors available for drupalcommerce. There will be more pages of payment modules, via the pagination at the bottom the page. If you have any errors come up with any of the payment processors. Put in a bug report in the issues at the right hand side of every drupal module project page.
Comments
Payment processors
For Credit card processors, go to the add-ons link in the menu of this website, which is here http://www.drupalcommerce.org/contrib then at the top select from the select box filter by module type, choose payment. You will then see credit card processors available for drupalcommerce. There will be more pages of payment modules, via the pagination at the bottom the page. If you have any errors come up with any of the payment processors. Put in a bug report in the issues at the right hand side of every drupal module project page.
As for PayPal
The module is here
http://drupal.org/project/commerce_paypal