Quick overview of Ring Lore
In the First age the original bad guy, Morgoth, put his power into Arda (Earth). This gave him a corrupting influence over Earth and its inhabitants. When he is finally bound and ejected beyond the doors of night, his power was left embedded in all things. (Side note: The whole story took place in a pre-biblical earth. This corrupting influence was only cleansed when the creator Eru-Illuvitar incarnated as Jesus. Not that JRRT believed this, it was the setting.)
In the Second Age Sauron, Morgoth’s chief commander, figures out how to tap into this ‘Morgoth element’. He then taught this method to a group of elves living in Hollin led by Celebrimbor. Originally a large but unspecified number of rings are created to tap into the Morgoth element and use it to accomplish some task or other. Gandalf originally thought Bilbo’s ring was one of these.
For the elves their primary concern was that, although they did not age and die, they eventually faded. This fading was never described in detail as to exactly what happened, but the only place it did not happen was in Aman (home of the Valar). The elves wanted the ability to preserve, prevent decay and fading. In fact Celebrimbor had already created a stone for Galadriel with preservative properties.
Eventually the elves, assisted by Sauron, made 16 great rings. These were designed to recreate the preserving ability of Aman. Sauron also tossed in a few powers not intended by the elves. These included a link to the spiritual world that the elves didn’t need, as they already lived in both the physical and spiritual world. There is some disagreement as to if there was any real difference between the 9 and the 7. In any case they were kept in separate locations.
At this point Sauron disappears for a while. Celebrimbor takes the opportunity to create the 3 greatest rings. Sauron had no part in their making, but Sauron’s methodologies were still used and they still used the Morgoth element as a power source. However they were more powerful than the 16, and they didn’t have the odd abilities thrown in by Sauron. One of the Three would not have made anyone invisible for example.
While Celebrimbor is finishing his greatest work, Sauron disappears and forges the One Ring on Mount Doom. The one is different in both purpose and power. Rather than preserve, the one is designed to dominate (it does have some preservation abilities as well). However the Morgoth element does not have the power to dominate the other ring holders, so Sauron places a large portion of his native power into the ring so that he can dominate the other ring holders.
At this point war begins and Sauron eventually captures the 16 and doles them out to those he would like to corrupt. He then settles down and begins a thousand odd year rule of almost all of Middle Earth; only few enclaves, mostly elvish, remain free. Eventually he fights a brief war with Numenor and is captured. But with his ring within a few years he corrupts them and they are destroyed (of course Sauron is too, but he gets better). He of course make two more plays for power and is defeated each time.
So was the ring a good idea? Well Sauron did rule over a really big area for a really long time. And he came within inches of doing it again a couple of more times. As long as the ring existed he couldn’t be permanently destroyed. But as we saw it was his one great weakness as well.