Yes, there are many resources available on this topic. Depending upon your interests, problem, goal, or idea, I would recommend different resources. Can you provide more information about your specific interest?
In its simplest definition, a knowledge graph is a representation of concepts and relationships between them. Concepts usually implemented by objects/classes/individuals and as Nodes in the graph. Relationships between the concepts are usually implemented as Object_Properties and as Edges in the graph.
For example, the “Semantic Web” is an attempt to apply a structure to store & represent knowledge that you would typically manipulate on web pages. If your interest is primarily web based solutions, you might find the book Programming the Semantic Web to be helpful
If your interest is deeper than web, you might be interested in The description logic handbook: theory, implementation, and applications. Description Logics are the basic formalism used in many of today’s ‘Knowledge Graphs.’ You can also search for resources on “Ontology” which is usually used by people synonymous with Knowledge Graph.
Computer Scientists call this area of research “Knowledge Management” or “Knowledge Base”