Can I put a link in the form to help them pay for their order?

However, the idea of people going into my PayPal account is not ideal for security. I thought I could put a link in the form to help them pay for their order would be best.
What do you suggest?

I want to have payments made for purchases through PayPal.  However, I don't want people to be able to access our actual PayPal Account.  

I was hoping to set up a link to go straight to the donate button to make payment for items.

How can I get this to work?

You can add a link to your form using the Text field. Here's a screenshot guide:

You can also add a link to your Thank You page after hitting the Submit button. Here's a sample:

Is this what you're trying to achieve?

I hope this helps.