The essays he wrote as an old man are very accessible. Incidentally, I read good deal of E.T.A. Hoffmann after a fling with Schumann's Kreisleriana. The Life and Opinions of Tomcat Murr is delightful and far ahead of its time.
For the Schumann piece, Cortot's recording can't be topped. I've heard 20+ others and nobody even comes close. Maybe If Richter had recorded it . . . Of modern versions, Perahia and Kissin play very well. Perahia's more dramatic; Kissin's unexpectedly unaffected.
+1 Cortot's Schumann is unsurpassed IMO, arguably better than his Chopin interpretations (actually I prefer Cziffra's Carnaval)!
It's such a shame that all the profound performances especially of the piano are all of such poor audio quality.... Perahia released an album about Cortot's masterclasses, it's definitely worth a listen as well...