I found this list on a B5 site:
THE NOVELS
(This first set of books was published by Dell, and are not generally regarded as canon,
with the exception of Books #7 and #9, for reasons noted in the entries.)
#1: Voices
#2: Accusations
#3: Blood Oath
#4: Clark's Law
#5: The Touch of Your Shadow, The Whisper of Your Name
#6: Betrayals
#7: The Shadow Within
#8: Personal Agendas
#9: To Dream in the City of Sorrows
(The following are the novels published by DelRey,
and as they are all based on original storylines by J. Michael Straczynski,
they are considered to be canon.)
Psi Corps Trilogy
Dark Genesis: The Birth of the Psi Corps
Deadly Relations: Bester Ascendant
Final Reckoning: The Fate of Bester
Legions of Fire
The Long Night of Centauri Prime
Armies of Light and Dark
Out of the Darkness
The Passing of the Techno-Mages
Casting Shadows
Summoning Light
Invoking Darkness
THE COMICS
The Price of Peace (Issues 1 - 4)
Shadows Past and Present (Issues 5 - 8)
Laser - Mirror - Starweb (Issues 9 & 10)
The Psi Corps and You (Issue 11)
In Valen's Name