The Importance of Warm-Ups - article by Jean-Pierre Mathez, editor of The Brass Bulletin
Fingering Chart by Ron Boerger
Fingering Chart - courtesy Yamaha
Fingering Chart - from Conn
Tuning
Tuning the Farkas Double Horn - by Philip Farkas. One of the many excellent articles on the Osmun web site.
Tuning the Double Horn - John Ericson's explanation of tuning the double horn.
Guidelines for Tuning the Horn - by Curtis Hammond of Morehead State University; pdf file.
Tuning the Horn - Selmer-Conn
Tuning the Horn - Hornstuff
Intonation Procedure for Tuning a Double Horn - article by Eldon Matlick
Understanding Brass Instrument Intonation - ditto
Tuning (3) - from the archives of hornplayer.net
Tuning the Double Horn in Just Intonation - pdf file
Embouchure
40 Embouchures from Farkas's Photographic Study of Embouchures - a list of the players
Embouchure 101 - article by John Ericson
Embouchure Health & Maintenance - article by Andrew Pelletier
Embouchure - Wikipedia article
Embouchure - The chapter on Embouchure from Wendell Rider's book, Real World Horn Playing. Also available in pdf form.
Embouchures.com - a primary resource for brass players with embouchure problems; excellent reference books for sale, including Broken Embouchures and Rehabilitating Embouchures.