Lesser Rings?
Mortals that posessed and wore the ruling ring-Isildur,
Smeagol/
Gollum,
Bilbo Baggins,
Frodo Baggins and
Sam Gamgee,certainly became"invisible"once
the ring was on their finger.
However this invisibility did cast some limitations such as a minor shadow.
Celebithil,you are on the right track,and with more research and or viewing previous posts regarding
the rings of power all your questions will,I am sure be answered.
The term "lesser"really is a misnomer,each ring was made with an inherent power equal to that of it's bearer.If a bearer of a ring was particularly powerful,the ring that the bearer wore expotentially increased their power over any given thralldom.
For example,the seven dwarven ring's were said to be the root cause of the seven great dwarvenhoard's.
The nine gave their bearer's greater scope for conquest and control amongst their fellow's,until the power of such ring's overtook their human form.
And the three,they were removed and hidden from
Sauron's prying,though that did not necessarilly negate their power-merely they were not used for fear of their corruption by the
ruling ring.
Finally there is the"ruling" ring.
I shan't do all the work for you,save to say that
the one ring certainly is not the first amongst equals.
Good Luck!
Regards

wimmerlaik