Short answers, pulled from the story.
Galileo Galilei first observed the rings of Saturn in 1610 using a telescope, though he could not identify them as rings. He described Saturn as appearing to be composed of three bodies and called the features the planet's "ears." Christiaan Huygens was the first to correctly describe them as a flat ring detached from the planet, publishing his hypothesis in Systema Saturnium in 1659.
Saturn's rings are composed of 99.9% pure water ice with a trace component of rocky material. The main rings contain particles ranging from micrometers to meters in size. The dense main rings extend from 7,000 km to 80,000 km above Saturn's equator and are as thin as 10 meters in places.
There is no consensus on the age of Saturn's rings. Data from the Cassini spacecraft suggests they formed within the last 100 million years, possibly as recently as 10 million years ago, rather than at the formation of the Solar System. Based on current rates of material loss, the rings may be completely gone within 100 to 292 million years.
The Cassini Division is a 4,800 km wide gap between the A Ring and B Ring, discovered in 1675 by Giovanni Domenico Cassini at the Paris Observatory. It is maintained by an orbital resonance with the moon Mimas: ring particles at the inner edge of the division orbit twice for every single orbit of Mimas, causing Mimas's gravitational pulls to accumulate and destabilize the particles' orbits.
The spokes are radial features in the B Ring that rotate almost in step with Saturn's magnetosphere rather than following normal orbital mechanics. The leading hypothesis is that they consist of microscopic dust grains suspended above the ring plane by electrostatic repulsion. Their precise cause is unknown; proposed triggers include lightning in Saturn's atmosphere and micrometeoroid impacts. The spokes appear seasonally, fading at Saturn's midwinter and midsummer and returning near equinox.
The source of the E Ring's material was determined in 2005 to be cryovolcanic plumes erupting from the "tiger stripes" of the south polar region of Saturn's moon Enceladus. The E Ring is distributed between the orbits of Mimas and Titan and is more than 2,000 km thick. It consists of microscopic particles of water ice along with silicates, carbon dioxide, and ammonia.
The Phoebe ring is a vast, faint disk of material just inside the orbit of Saturn's moon Phoebe, announced in October 2009. It was discovered using NASA's infrared Spitzer Space Telescope by Anne J. Verbiscer, Michael F. Skrutskie, and Douglas P. Hamilton. Unlike Saturn's other rings, the Phoebe ring orbits in a retrograde direction and is tilted 27 degrees from the main rings, lying instead in the plane of Saturn's orbit.