Regulus is known as the "Heart of the Lion", and is the brightest star in Leo, the Lion. Leo is perhaps the easiest constellation of the Zodiac to identify, and Regulus is one of the easier stars to find. Using the Big Dipper, a line down through the two stars forming the rear of the handle will point down towards Regulus, in the same way that the front two stars point up towards Polaris.
Regulus is one of the four brightest stars to appear in the Zodiac, along with Antares, Spica and Aldebaran. Because it is has a slightly northern declination, and is mostly in the sky in winter, Regulus is much more obviously bright than Antares or Spica, even though their magnitude is greater. This at least is true in the Northern Hemisphere, in the Southern Hemisphere, the situation is reversed.
Another feature of Regulus that makes it important for observational astronomy is that it lies very close to the plane of the ecliptic, and thus is often passed very closely by the moon and planets, and is sometimes occulted by them.