The best Magento theme documentation on ThemeForest. It also describes selected Magento features which you need to know when starting to work with Magento.
Use Ultimo as a starting point for your custom projects. Unlike many other themes, Ultimo lets you create multiple custom sub-themes (theme variants) for your clients.
This is a custom landing page: a CMS block which can replace category products. You can put your own content here: text, HTML, images - whatever you want. You can create landing page for every category.