I've noted the link between the songs on Bob's greatest album and the Romantic poet William Blake several times here and elsewhere, but this is not necessarily my original perspective. I've been reading Blake closely (32 years) almost as long as I've been listening to Bob (42 years), so spotting affinities between them has been part of my appreciation of both artists.
However, in conversation with Allen Ginsberg, he told me that Bob specifically spoke to him at length and with great passion and curiosity about Blake around the time of JWH (and like an idiot, I only notice now that the abbreviated title resembles JahWeH--live and learn), especially Songs of Innocence and Experience.
My recommendation would be to buy Blake's Complete Poems in either the Penguin Classics or Oxford Classics edition--you will cherish the book the rest of your life. Blake's poems are sometimes strange and obscure, other times almost mindlessly simple--he boasted that children appreciated his poems best--but the depth of vision and originality put him among the very greatest writers in English. The places to start reading with Bob Dylan in mind would be Blake's prose poem THE MARRIAGE OF HEAVEN AND HELL and SONGS OF INNOCENCE AND EXPERIENCE.
MARRIAGE is a bold visionary statement, and the "Proverbs of Hell" section is probably the most influential passage. The direct expression and concise imagery were among the factors that caused Bob to simplify his own writing technique post-1966.
In the SONGS, "London" is probably the greatest lyric, but "The Tyger" "The Chimney Sweep" "Little Lamb" and many others show an economy of expression and a lyric force that have influenced Dylan's songcraft. Many of these have been put to music by Ginsberg, Vaughan Williams, William Bolcomb, and other composers and musicians.
Blake is not the only influence on Dylan--Hank Williams is just as important to JWH in many ways--but Blake/Dylan make a good comparative study, as the former was the rebel supreme of his time, maybe of all time, and among the most original artists who have ever lived. Most of the superlatives people throw around about Bob Dylan overstate the case, but Blake really is that great and important, and his influence has only grown since his relatively obscure life and death.
On JWH, the three verse structure to the songs, the concise character studies and narratives in Drifter's Escape, Lonesome Hobo, Wicked Messenger and All Along the Watchtower show Dylan at his most powerfully poetic level of songwriting.
Oh, help me in my weakness I heard the drifter say
As they carried him from the court room and were taking him away
My trip has been a pleasant one, and my time it isn't long
And I still do not know what it was that I've done wrong
These lines follow a basic seven beat poetic measure, with a rest in the first line and some unstressed syllabic compression in the second. The third and fourth lines follow the fourteen syllable, seven stress form most closely, but still vary from a strict iambic rhythm.
Blake commonly used this poetic form in two ways--as a standard ballad lyric form of four/three/four/three with shorter lines, and as the longer seven stress line in his visionary poems like "Visions of the Daughters of Albion." Bob does the same thing--Gates of Eden is in the longer format, as is Tangled Up In Blue, while JWH songs are often printed in the ballad lyric form.
Anway, those are some of the affinities between Blake and Dylan. You'll find many on your own, I'm sure. Some of the relationship comes through Bob's relation to Ginsberg and the Beats, in addition to Bob's own study and interest.
Van Morrison is another big Blake fan.
Hope that helps.