Login to your PayPal account and click the Wallet link. Here you can add bank accounts and credit/debit cards.
When you add your bank account info it will ask if you want to instantly verify it. With BoA you'll be able to do this by logging in with your online banking. Then the account will be attached to PayPal and fully verified.
You might find this PayPal Quick Tip about protecting bank accounts interesting:
Angell EYE - www.angelleye.com PayPal Partner and Certified Developer - Kudos are Greatly Appreciated!