Learn The Alien Languages Of Star Trek: A Masterpost

Learn the Alien Languages of Star Trek: a Masterpost

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Vulcan Language Official Tumblr (No longer active, but still good info)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