SmugMug is very powerful, allowing you to personalize your site beautifully and quickly without having to learn HTML/CSS, Javascript, etc.
But maybe you want an advanced look the tools don't quite allow by default. We've got plenty of resources to help with that, too.
Browse our Personalizing category for lots of answers and how-tos here on our help site.
Or search for more great info in our SmugMug Customizations Forum at dgrin.com. It's a great place to ask for help, trade design ideas, and discuss how to get the look you want with other users, customization experts, and SmugMug Heroes.