If you don't have an accounting software package installed on your PC, sending an invoice to someone usually involves slaving over Word or Excel to come up with something that looks vaguely acceptable.
If you'd rather make your life easy, check out Invoice Berry at www.invoiceberry.com. Once you've signed up, you can create an invoice to any client quickly and easily, just by filling in the online form. Sales tax is calculated automatically if required.
When you're done, you can download the finished invoice as a PDF file to print or email.
You can even customize your invoices by uploading your logo to the site.
If you only need to invoice 3 different clients, Invoice Berry is totally free. You can delete clients that you no longer need to invoice, of course, but you'll lose the history and reporting functionality that accompanies them.