Where to place the admin screens for a module
There is a handbook page that covers where you should place these menu items.

See Information architecture

I won't copy and paste the info here as it is too long. You also don't provide any info on what your module is about, so I can't even paste a excerpt that pertains directly to your issue. 

The handbook page should be considered the canonical source for this info.

EDIT:

While these are guidelines, I don't think that they are very cut and dry. I would personally place the menu where the other two major tag cloud modules (Cumulus and TagCloud) place theirs: admin/config/content and keep them both in the same spot (one as a child item of the other)