I'd additionally suggest joining the SWI Prolog board. They are a kind and generous community. Jan Wielemaker -- the principal contributor -- often answers questions directly.
Meanwhile, SWI Prolog is a mature and commercially used open-source Prolog distribution. It has a huge number of libraries which will come in useful for real world applications.
guys! I'm into logic and philosophy of language applied to psychology. stumbled on this thread from googling prolog! please, can you recommend a programming Prolog video intro for me? I'm interested in programming (my undergrad is cs) immediately and applying Prolog to write psycho-philosophical case studies.