Installation steps:

1. Enable this module
2. Go to Configuration -> Web Services -> PayPal donation 
  (admin/config/services/paypal_donations)
3. Provide your PayPal accounts for the different donations and save
4. In Blocks (admin/structure/block) you have two different blocks for 
  the single and recurring donations, enable them wherever you want.
5. Test your module with a sandbox PayPal account, once ready you need to 
turn to "Production" mode in the configuration page