[Kalimac]

Not a silly question at all, TG! These things are always interesting (like in those fairytales where a giant's power will be vanquished if the hero just plucks three golden hairs off of his head; how did the hairs get to be so powerful, and more to the point, WHY?)

As has been said before, rings are traditionally associated with power; one theory is that this is simply because a ring is an unbroken circle which would be a nice shorthand symbol of strength - something with no beginning or end, or obvious vulnerabilities. As for why Sauron would choose a ring (besides the fact that everybody else was doing the same thing; seven for Dwarves, three for Elves and so forth) - well, look at the practical side of things. It's small, light, easily carried and concealed and, unlike a sword, hard to knock out/off of one's hand or accidentally drop during battle (Isildur managed to get it off his hand, of course, but only by getting close to Sauron than he had ever wanted and by physically cutting off a finger). And if you DO lose it, it's so small that the odds are rather against anyone else finding it, especially since the Ring has so much of your nature in it and can call out to you, so to speak.