To inaugurate this thread, here are links to some of this board’s preexisting dialogues on these topics: 

 
Lynch the Mason
http://www.2000revue.com/community/topic.cfm?topicid=3379

Buddhism in Twin Peaks 
http://www.2000revue.com/community/topic.cfm?topicid=5259

Owl Cave Glyph / Briggs and Log Lady Tattoos
http://www.2000revue.com/community/topic.cfm?topicid=5667

Eyes Wide Shut / Rainbows / Theosophy
http://www.2000revue.com/community/topic.cfm?topicid=5309

The Did You Notice Compendium - Episode 17 (Dweller on the Threshold discussion)
http://www.2000revue.com/community/topic.cfm?topicid=2789

Mark Frost and his contribution to TP
http://www.2000revue.com/community/topic.cfm?topicid=3628

Season 2 episode 20 (scene of Windom Earle interrogating Major Briggs)

   Windom Earle: What is the capital of North Carolina?
   Major Briggs: Raleigh
   Windom Earle: Fat load of good that'll do me.

The capital city is named for Sir Walter, a luminary who is purported to have dabbled in the occult.  In Twin Peaks however, this is more likely the screenwriter’s reference to A.S. Raleigh, who authored numerous books on Hermeticism and Alchemy.

Windom Earl’s wife’s name was Caroline Powell.  Another author of books on the subjects of Alchemy and the mysteries is Neil Powell.

Two sets of conspiring characters in TP were named Mike and Bob[by].  Cooper inferred that the letters placed under the victims’ fingernails spelled an abbreviation of the surname Robertson.  In 1930, renowned English poet and writer, Michael Roberts published a collection of poems; several of which contained passages with Hermetic subject matter, including one such poem that was an homage to Alchemist, Nicolas Flamel.  Roberts was also a mountaineer, and his descriptions of mountain and nature settings play heavily in these poems.         

Our central character shares part of her name with:

Manly Palmer Hall, the venerated twentieth century luminary of mystic and esoteric scholarship, founder of the Philosophical Research Society , lecturer and author of numerous illustrious works, including the 1928 publication, The Secret Teachings of All Ages : an Encyclopedic Outline of Masonic, Hermetic, Qabbalistic and Rosicrucian Symbolical Philosophy. 

Link to publisher's site for Master of the Mysteries , the well-received 2008 book by Louis Sahagun:

Articles by Mitch Horowitz:

The Inscrutable Manly P. Hall:  The Author of The Secret Teachings of All Ages Remains an Enigma

Bringing the ‘Secret Teachings’ Into the 21st Century:  The New Life of a Great Book 

The 'Secret Teachings' Reborn:  The Mysterious Life and Mission of Manly P. Hall

In the pilot episode, while composing poetry, Donna's sister Harriet asks "Donna, which do you like better, the blossom of the evening or the full flower of the evening?" 

Harriet later says to herself "...now that some time has passed, I like the full blossom of the evening."

Michael Roberts poem about Alchemist Nicolas Flamel contains a verse "Now that spring is over, show me some blossom that defies the sun."