Some hot links for handling the SharePoint 2013 Search and its API.
- Search in SharePoint 2013
- SharePoint 2013 Search REST API
- [MS-SRCHCSOM]: Search Client Query Protocol
- Building search queries in SharePoint 2013
- Query variables in SharePoint Server 2013
- Sorting with Search Query in Content By Search Web Part
- Configuring SharePoint 2013 Search REST API for anonymous users
- Introducing Indexed property bag in SharePoint 2013 – a searchable collection of properties