Sacred Heart of Jesus links

History:

All About the Sacred Heart of Jesus
Catholic Encyclopedia
Devotion to the Sacred Heart of Jesus
History & Devotion to the Sacred Heart of Jesus
Human Heart and the Sacred Heart
Wikipedia

Outsider and Visionary Artist who have featured the Sacred Heart of Jesus in their art:

Carrie Ann Baade
Vicki Berndt
Salvador Dalí
Henry Darger
Arthur Durkee
Daniel Martin Diaz
David Graham
Alex Grey
Riccardo Olvera Jiménez
Jeff Koons
Norbert Kox
Elizabeth McGrath
Odilon Redon
Antonio Roybal
Jos Sances
William Thomas Thompson

Organizations featuring Sacred Heart fine, religious and outsider art:

American Folk Art Museum
American Vision Art Museum
Electronic New Testament Educational Resources
The Foundation for Sacred Arts
National Museum of Catholic Art and History
Nazareth Studio
Photo Bucket
St. Michael Institute of Sacred Heart
The Anthony Petullo Collection for Self-Taught and Outsider Art
The Center for Intuitive and Outsider Art
The Art of Divine Mercy
The John Michael Kohler Arts Center
The Mennello Museum of American Art
Religious Art Gallery

Holy Cards:

He Gently Calls Us
Holy Cards for Your Inspiration

Holycardheaven.blogspot.com
Pierluigi Stradella
Saints Unlimited

Devotion to the Sacred Heart of Jesus:

All About the Sacred Heart of Jesus
Apostles of the Sacred Heart
Cathedral of the Sacred Heart, Richmond, Virginia
Catholic Tradition
Congregation of the Sister Servants of the Most Sacred Heart of Jesus
Consecration
The Divine Mercy
Fish Eaters
Heart to Heart
The Imitation of the Sacred Heart of Jesus
Maryvale Institute
Oblates of St. Francis de Sales
Sacredheart.com
Sacred Heart Organization Israel

Sacred Heart Prayer
Sacred Heart Schools
Sacred Heart Sisters
Sisters of Carmel
Society of the Sacred Heart
Visions of Jesus Christ