Here are some basic templates created as starting points for building sites with Spark. These are included in the Spark download but you can preview them below too.
The most basic is bones, which is as basic as it gets. Go nuts.
The basic Spark template with just enough to get you started. Includes a basic navigation bar example and some content for you to replace.
A bit more complex, the Hero template contains an example hero (surprisingly) and some of the elements you will find in Spark including nested rows and a centered navigation bar.