How would I create a particle field that moves and looks like Saturn's (planet) ring

I'm completely new to Particle systems, and it seems what ever I do I cannot seem to get the desired effect, I'm trying to create a planet, that has rings similar to Saturn... made up of a particle system. Does anyone have any idea on where to start, and how to achieve this.

Perhaps you could create a mesh in the shape of the ring, and then use a Mesh Particle Emitter to emit particles from the vertices of that mesh.

You'd need to make sure the mesh was subdivided to a fine enough degree to give an even spread of vertices across and around the ring.

If you make sure that the particles are not set to 'simulate in world space', then you could make all the particles orbit the planet by simply rotating the particle emitter GameObject. (If the particels simulate in world-space, then their position isn't affected by subsequently moving the emitter GameObject).

Also, if you set the particle system to 'one shot', and ensure the particle system GameObject doesn't have a particle animator component, then the particles will be spawned immediately, and persist indefinitely. (See my answer about creating a nebula effect here for more information on that).