A friend, knowing I was 'in-the-market' for a publishing house, gave me a listing of publishing houses and their imprints with titles and such. An invaluable resource. It still requires work; I have to research the names before I send anything out, as life in the publishing industry changes from day to day.
The listing answered one question I had. What do I do about sending my MS to the same house? Many publishers today have various, what I call divisions. I wasn't sure what to do about this. For instance, Scholastic has their main house, but they have other divisions, notably, Blue Sky Press, which would fit 'Sorrysorrysorry.'
I looked up imprint and that's the word publishing houses use for divisions. Sometimes, imprints are the result of a larger publisher buying up a smaller publisher, yet wanting to keep the 'niche' the smaller publisher had. Imprint is the 'trade' name for a different division. Imprints are also used for consumer marketing.
The listing I received said that an MS should be sent to the different imprints of the publishing house. So that answered my question. If I send 'Sorrysorrysorry' off to, say, Scholastic, then, after a reasonable time allowed for a response, I can send it off to Blue Sky Press, even though it is part of the Scholastic network. Interesting. I learn something new everyday.
I hope this helps.
Life is learning.
PS - Once again, a bit of research is needed. One of the publishers I looked at does NOT want an MS sent to each of their imprints.