Don't have a Paypal account?
LSF uses Paypal as a payment clearinghouse. It benefits the foundation, which doesn't have the cost of a Merchant Credit account, and it benefit customers.
It is very simple to set one up. Go to paypal.com and click on "Sign Up" at the very top of the page, left. Then just follow instructions, filling in your information. One page will do it: you will immediately have an account. You will then be asked how you wish to pay, and if you wish to set up automatic payment from your credit card or from a bank account you can do this. If you do not, you can use your paypal account anyway, but you will just have to enter your payment information every time you pay a bill.
How do you get a bill? It will come to you via the email address you used to place your order with LSF and will also go to your paypal account at the same email address, so you should order with the same email as is on your paypal account. When the email bill arrives, you just have to log into your paypal account (the email bill you get from paypal will also make this easy, just one click), see the bill, click on "Pay ***" in the "Order status/Actions" column, and follow the simple instructions to pay. It is very simple and clean, and does not expose your credit card or bank account information to any vendor.