Many people hold varying opinions on William Blake and his poetry. My opinion is that he used simple language to create romantic visions about the natural world he loved. And he created some pretty unique ideas such as Urizen.
I personally have not read all the poems in this volume (although I've read as many as I could) because there are many drafts and different versions of poems. The ones I have read I have enjoyed very much so and not simply because my favourite high school teacher thoroughly recommended them.
If you enjoy poetry Blake is a must read. He was a misunderstood visionary who has some interesting things to say whether you agree or disagree. His poems attacking the industrial movements are particularly fascinating.