takes some digging, but google is your friend. this is a really brief article, but it mentions a book you could use. i don't know anything about the elven star myself, but try typing in something like 'elven star wicca' or 'elven star faerie' or something into a search engine. [just thought of another one, if it's pertaining to faerie magic, look up faerie magic books]
he Elven Star, or seven-pointed star, is found in some branches of the Faerie tradition of Wicca. However, it has different names and can be associated with many other magical traditions.
According to The Element Encyclopedia of Secret Signs and Symbols, the Elven Star (or Faerie Star) is also representative of the seven stars called the Pleiades. It is also a reminder that seven is a sacred number in many magical traditions -- it is connected with the seven days of the week, the seven pillars of wisdom, and many other magical theories. In Kabbalah, seven is connected to the sphere of victory. Aleister Crowley used a septagram as the emblem of his Order of the Silver Star.
In modern Pagan practice, this symbol can be used to keep information hidden from the prying eyes of the outside world. Use it on your Book of Shadows, to keep the contents safe, or on an amulent to prevent others from reading your thoughts.
I do not know to much about the elven star, but I do know about the elven tribes, they were a tribe of people they were not like elves seen on cookie commercials, no, they were a group of people doing magick called elven magick, they believe in purity and power, I heard their magick is pretty powerful, I should check out more about the elven magick myself, but they also were a tribe from Ireland. Hope that helps. I also heard a rumor that they also were found in america it may have been a tribe of native americans or possibly people that just moved to america, not sure if that's entirely true but I am certain that they came from Ireland.
Crowley is most often cited when one researched the septagram at first and is also found in the Kabbalah. The bit about the stars tends to come along with New Age thought.
Brad, you're thinking of the Tuatha D Danann and they were not elves. Elves are often equated with Faeries, but they are not the same. Elves are prominantly found in Norse lore (Alfar, Svartalfar, Dokkalfar, etc).
In Alchemy, the septagram is used to show the cycle of the seven classical planets (not always in this order); Sol, Luna Mercury, Venus, Mars, Jupiter, and Saturn. It made use of planetary hours, among other things.