I have found the function reference documentation, it's actually included with the plugin. GD Star Rating is a great plugin, but I must say I agree with dskvr. It's been a very long day trying to find everything...
To access function reference:
Navigate to GD Star Rating in the sidebar of WP admin, then to "Builder". At the bottom of the builder there is the following:
List of all functions with additional parameters:
The word 'functions' links to the function reference.
Even with this information in hand I still struggled to add stars to my theme in the way I wanted to. In this instance I needed to just display small stars with the post's rating on main pages with excerpts, and not to allow ratings on these pages.
After digging around on the web for quite some time I found this article:
The following code added into the theme generated stars as required:
$postRatingData = wp_gdsr_rating_article(get_the_ID());
"max_value" => gdsr_settings_get('stars'),
"size" => 12,
"vote" => $postRatingData->rating
Thanks Tom Auger!
You can see the ratings in action below thumbnails on all main pages (not single) at the link below. Settings are as above, with 12px stars.