Vulcan (Vulkhansu)

• Vulcan Language Research Project
  
• Vulcan Language Dictionary
  
• Vulcan Writing Systems at Omniglot
• Korsaya
  
• Vulcan Language at Memory Alpha
  
• Vulcan Language Institute
• Vulcan Language Official Tumblr (No longer active, but still good info)

Cardassian (Kardasi)

• Cardassian Language Tumblr
  
• Kardasi Dictionary
• Kardasi Grammar Summary
• Cardassian Writing System Part 1
• Cardassian Writing System Part 2
• Cardassian Writing System Part 3 (Numbers)
• Kardasi Quizlet Class
• Cardassian Language at Memory Alpha

Klingon (Klingonese)

• KlingonTeacher on Youtube
  
• Learn Klingon Facebook Group
  
• Klingon Teachings 
  
• Klingonska
  
• The Klingon-English Dictionary by Marc Okrand PDF
  
• Klingon Language at Memory Alpha
• Duolingo Klingon Course
  
• Klingon Language Institute
• Klingon Language Assistant App (For Android Phones only)
• Klingon for the Galactic Traveler by Marc Okrand
• Conversational Klingon by Marc Okrand
  
• Power Klingon by Marc Okrand
  

Romulan (Rihannsu)

• Imperial Romulan Language Institute
  
• Romulan Writing System on Omniglot
• Central Institute of the Romulan Language
  
• Romulan Language and Culture Institute
  
• Romulan-English Dictionary
• Romulan Language at Memory Alpha

Ferengi

• Ferengi Language at Memory Alpha
• Ferengi Writing System Part 1
  
• Ferengi Writing System Part 2
  

Bajoran

• Bajoran Language Project
• The Bajoran Language File
• Bajoran-English Dictionary
• Bajoran Language at Memory Alpha

Trill

• Trill Language at Memory Alpha
  
• Trill Language at Holowiki (Not sure how accurate this is)

Dominionese

• Dominionese at Memory Alpha
  

Borg

• Borg Language at Memory Alpha
  

Andorian

• Andorian-English Dictionary
  
• Andorian Language at Memory Alpha
• Andorian Languages at Memory Beta