Here are articles written by prominent Vocal Coaches:

Additional Articles by Vocal Coaches
This is an article by Beth Trollan, a singer/songwriter, actress and vocal coach based in New York City. She offers insightful tips on both singing and performing.
This is an article by vocal coach Jessica Ford of Nashville, TN, who talks about how you can keep your voice in good condition and health, to keep from getting hoarse.
This is an article by vocalist Ann Ruckert, who is an award-winning studio musician and jingle singer based in New York.
This is an article by vocal coach Bob Rose of San Francisco, CA, who talks about how you can keep your voice in top, physical shape.
This is an article by vocal coach Robert Lunte of Seattle, WA, who discusses the difference in techniques between the singing and speaking voices.
Here is a second article by vocal coach Bob Rose of San Francisco, CA. This is a very comprehensive article on how you can breathe properly, to maximize your vocal support for singing.