Many poets write about writing poetry; Allan at Rough Days links to a long list. This makes sense, because poets spend a lot of time writing poems. But few poets write about reading poetry, which is odd, because poets (one hopes) spend even more time reading poems. The best poem I know about reading poetry is by J.V. Cunningham. It says that the poem lives only in the mind of the intelligent reader, not on the page, and that to reconstruct the poem, to enter so far into the thoughts of someone else, is itself a creative act.
Poets survive in fame.
But how can substance trade
The body for a name
Wherewith no soul’s arrayed?
No form inspires the clay
Now breathless of what was,
Save the imputed sway
Of some Pythagoras,
Some man so deftly mad
His metamorphosed shade,
Leaving the flesh it had,
Breathes on the words they made.