Hi Kori,
You don't necessarily have to be an administrator to customize. However, your user does need access to the Customize tab, the Screens tablink and the table and screen that you wish to customize. If you don't have these permissions the admin will have to set this for you. or perform the customization. As for sending attachments, which type of attachment do you want to send and from which screen?
For example, sending a pdf of an estimate only requires a couple of changes. First you'll need to add the generate report action (same action used on the print preview button) and place it before the Send Email action on the Save & Email button. This will generate the estimate you wish to send and save it an action result. Then all you need to do is edit the Send Email action and set the attachment as the action result for your report.
If you can tell us a bit more about your end goal here, we can provide solution that might fit your needs.
- Adam