I need the ability for customers to contact me. How can I create a custom contact form to collect the information I need?
When you complete the Customer Contact Info section in the Pros tab in your Control Panel, that will set up the Contact link in the SmugMug footer, which will open a contact form that will be sent to the customer contact email address you keep on file. You can also make it so that you can create a navigation bar button that points to that same contact form, using this customization: http://www.dgrin.com/showthread.php?t=180288 .
There are also other ways to do this, for example, creating an HTML only gallery (using # 39 on this page: http://help.smugmug.com/customer/portal/articles/93381-most-requested-customization-tips), and then embedding a third-party contact form as HTML in the gallery description. Wufoo.com is one site where you can create a free, embeddable contact form. You could then link to this gallery in a "contact me" nav bar button.