>>> It would be nice to have a mode in which you can browse through all
>>> the various character sets, move to a character you are interested in,
>>> and ask how to input it.
>>
>> This is already implemented by dynamically generated Info manuals
>> in info-help.el.
>>
>> You can browse through all available character sets using Info menus
>> where each character set and each character has a separate Info node
>> containing the full information.
>
> Details?
> Documentation?
> NEWS entry?
> How do I do that?

It's unfinished since after posting it I got no reaction.
If it turns out to be useful, I could finish it.
Please note that this virtual Info manual is not a replacement
of Help.  Help is still better to quickly get the information,
but for browsing Info is better.