Some General Background
A curated list of topics relevant to gaining general background relevant to OpenCog on Wikipedia: OpenCog By Way of Wikipedia
Books Directly Related to OpenCog AI
Many of the ideas underlying OpenCog originally emerged from Ben Goertzel's writings on AI, cognitive science and related topics.
The books Engineering General Intelligence vol. 1 and | Engineering General Intelligence vol. 2, published in 2014, contain a fairly detailed description of the CogPrime AGI design, which is briefly reviewed here , and which was one of the main motivations for developing OpenCog.
The books Probabilistic Logic Networks (note free pdf here, a partial wikifization here and errata page here) and Real World Reasoning (on this wiki site in full at the Real World Reasoning page) review mathematical and conceptual ideas underlying OpenCog's PLN (Probabilistic Logic Networks) subsystem.
It is recognized that the above books are pretty expensive to buy. The core contents of these books are expected to appear on this wiki sometime soon. Enterprising readers can also find free PDF copies at various download sites on the web, for example
(Of course, nobody contributing to this wiki would ever advocate downloading books from such websites without carefully checking copyright law first; we merely point out these links for your general entertainment and edification!!)
Papers Directly Related to OpenCog AI
A number of papers have been published reporting ideas or experiments using OpenCog; this list is not necessarily complete. (Most of these papers are available online somewhere or other in PDF form, even though nobody has bothered to insert links to them here yet. Use a search engine! Also, much of this material, up till mid-2013 anyway, is contained in the Engineering General Intelligence volumes as well)
- Goertzel, Ben and Gino Yu (2014). A Cognitive API and its Application to AGI Intelligence Assessment, Proceedings of AGI-14, Springer
- Harrigan, Cosmo, Ben Goertzel, Matthew Ikle and Amen Belayneh (2014). Guiding Probabilistic Logical Inference with Nonlinear Dynamical Attention Allocation, Proceedings of AGI-14, Springer
- Goertzel, Ben, David Hanson and Gino Yu (2014). A Software Architecture for Generally Intelligent Humanoid Robotics. Proceedings of BICA-14. Procedia Computer Science, Springer. Earlier version in proceedings of Workshop on General Intelligence for Humanoid Robotics, IEEE-ICRA 2014, Hong Kong.
- Sadeghi, Keyvan and Ben Goertzel (2014). Uncertain Interval Algebra via Fuzzy/Probabilistic Modeling, FUZZ-IEEE 2014, Beijing, July 2014
- Goertzel, Ben and Gino Yu (2014). From Here to AGI: A Roadmap to the Realization of Human-level Artificial General Intelligence. IJCNN, Beijing, July 2014
- Goertzel, Ben et al (2013). The CogPrime Architecture for Embodied Artificial General Intelligence. Proceedings of IEEE Symposium on Human-Level AI, Singapore
- Goertzel, Ben, Ted Sanders and Jade O’Neill (2013). Integrating Deep Learning Based Perception with Probabilistic Logic via Frequent Pattern Mining, Proceedings of AGI-13, Springer
- Syntax-Semantic Mapping for General Intelligence: Language Comprehension as Hypergraph Homomorphism, Language Generation as Constraint Satisfaction. Ruiting Lian and Ben Goertzel. Procedings of AGI-12.
- Perception Processing for General Intelligence: Bridging the Symbolic/Subsymbolic Gap, Ben Goertzel. Proceedings of AGI-12
- Pattern Mining for General Intelligence: The FISHGRAM Algorithm for Frequent and Interesting Subhypergraph Mining. Jade O’Neill and Ben Goertzel. Proceedings of AGI-12.
- Cai, Zhenhua, Ben Goertzel, Changle Zhou, Yongfeng Zhang, Min Jiang, Gino Yu (2011). Dynamics of a computational affective model inspired by Dörner’s PSI theory. Cognitive Systems Research.
- Goertzel, Ben (2011). Integrating a Compositional Spatiotemporal Deep Learning Network with Symbolic Representation/Reasoning within an Integrative Cognitive Architecture via an Intermediary Semantic Network. Proceedings of AAAI Symposium on Cognitive Systems, Arlington VA, http://goertzel.org/cognitive_systems_2011.pdf
- Goertzel, Ben, Joel Pitt, Jared Wigmore, Nil Geisweiller, Zhenhua Cai, Ruiting Lian, Deheng Huang, Gino Yu (2011). Cognitive Synergy between Procedural and Declarative Learning in the Control of Animated and Robotic Agents Using the OpenCogPrime AGI Architecture. Proceedings of AAAI-11 http://goertzel.org/Goertzel_AAAI11.pdf
- Goertzel, Ben (2011). Lifelong Forgetting: A Critical Ingredient of Lifelong Learning, and its Implementation in the OpenCog Integrative AI Framework. Proceedings of AAAI-11 Workshop on Lifelong Learning
- Ikle, Matthew and Ben Goertzel (2011). Nonlinear-Dynamical Attention Allocation via Information Geometry, Proceedings of AGI-11, Lecture Notes in AI, Springer Verlag 
- Cai, Zhenhua, Ben Goertzel and Nil Geisweiller (2011). OpenPsi: Realizing Dorner’s ”Psi” Cognitive Model in the OpenCog Integrative AGI Architecture, Proceedings of AGI-11, Lecture Notes in AI, Springer Verlag 
- Goertzel, Ben, Joel Pitt, Zhenhua Cai, Jared Wigmore, Deheng Huang, Nil Geisweiller, Ruiting Lian, Gino Yu (2011). Integrative General Intelligence in a Minecraft-Type Environment. Proceedings of BICA-2011, Arlington VA, 
- Ruiting Lian, Ben Goertzel, Rui Liu, Michael Ross,Murilo Queiroz, and Linas Vepstas. Sentence generation for artificial brains: a glocal similarity matching approach. Neurocomputing, Dec 2010 
- Ikle’, Matthew and Ben Goertzel. Grounding Possible Worlds Semantics in Experiential Semantics. Proceedings of the Third Conference on Artificial General Intelligence, Atlantis Press 
- Goertzel, Ben, Cassio Pennachin, Samir Araujo, Ruiting Lian, Fabricio Silva, Murilo Queiroz, Welter Silva, Mike Ross, Linas Vepstas, Andre Senna. A General Intelligence Oriented Architecture for Embodied Natural Language Processing. Proceedings of the Third Conference on Artificial General Intelligence, Atlantis Press
- Geisweiller, Nil and Ben Goertzel. Uncertain Spatiotemporal Logic for General Intelligence. Proceedings of the Third Conference on Artificial General Intelligence, Atlantis Press
- Goertzel, Ben, Hugo de Garis, Cassio Pennachin, Nil Geisweiller, Samir Araujo ,Joel Pitt, Shuo Chen, Ruiting Lian, Min Jiang, Ye Yang, Deheng Huang (2010). OpenCogBot: Achieving Generally Intelligent Virtual Agent Control and Humanoid Robotics via Cognitive Synergy. Proceeedings of ICAI 2010, Beijing. 
- Goertzel, Ben. OpenCogPrime: A Cognitive Synergy Based Architecture for General Intelligence. International Conference on Cognitive Informatics, Hong Kong, 2009 
- Ikle, Matthew, Joel Pitt, Ben Goertzel and George Sellman. Economic Attention Networks: Associative Memory and Resource Allocation for General Intelligence. Proceedings of the Second Conference on Artificial General Intelligence, Atlantis Press.
- Looks, Moshe and Ben Goertzel. Program Representation for General Intelligence. Proceedings of the Second Conference on Artificial General Intelligence, Atlantis Press.
- Goertzel, Ben. OpenCog NS: A Deeply-Connected, Hybrid Neural-Symbolic Architecture, Proceedings of BICA-2010, Alexandria VA
- Goertzel, Ben . A Pragmatic Path Toward Endowing Virtually-Embodied AIs with Human-Level Linguistic Capability, Special Session on Human-Level Intelligence, IEEE World Congress on Computational Intelligence (WCCI) Hong Kong, 2008
- Goertzel, Ben and Pennachin, Cassio . An Inferential Dynamics Approach to Personality and Emotion Driven Behavior Determination for Virtual Animals. The Reign of Catz and Dogz Symposium, AI and the Simulation of Behavior (AISB), Edinburgh, 2008
- Goertzel, Ben, Cassio Pennachin, Nil Geissweiller, Moshe Looks, Andre Senna, Ari Heljakka, Welter Silva, Carlos Lopes . An Integrative Methodology for Teaching Embodied Non-Linguistic Agents, Applied to Virtual Animals in Second Life, in Proceedings of the First AGI Conference, Ed. Wang et al, IOS Press
- Ikle’, Matthew and Ben Goertzel . Probabilistic Quantifier Logic for General Intelligence: An Indefinite Probabilities Approach, in Proceedings of the First AGI Conference, Ed. Wang et al, IOS Press 
- Hart, David and Ben Goertzel. OpenCog: A Software Framework for Integrative Artificial General Intelligence, in Proceedings of the First AGI Conference, Ed. Wang et al, IOS Press 
Pointers on AGI
Some background information on Artificial General Intelligence in general can be found on the Resources page on the AGI Society website.
Hard and cold Universal AI theories (usually abstracting away computational resource limits)
- Ray Solomonoff Universal Induction. Key papers (well, those that I have read):
- Marcus Hutter's AIXI Universal Artificial Intelligence
- Jurgen Schimhubber's Goedel Machine
Good prerequisites (sorry I don't have specific books to recommend)
- Goedel's Incompleteness Theorems. The original paper (translated in English) can be found here On Formally Undecidable Propositions Of Principia Mathematica And Related Systems.