The Numenoreans Return to ME

Just for laughs I'm trying to construct for myself a better picture of what the Numenoreans were doing in ME during the Second Age and I'd like to solicit your opinions. If you have specific references that is always cool - it's nice to differentiate between pure speculation and "educated" speculation, but I don't think there is a lot of material on the subject (there's a lot I haven't read - what I know is from the Silmarillion and the LoTR appendices). Let me lead into what I'm curious about:

I know that the Numenoreans started returning to ME after 1200 and began to make more permanent dwellings shortly thereafter. I wonder where these would have been? My impression is that the Numenoreans mostly stayed out of Eriador and built havens along the more southerly coasts. Is there any talk about the them during Sauron's first incursion into Eriador (other than that they lent aid to Gil-Galad)?

Later, when things were more divisive the faithful Numenoreans gathered in (among other places) what would eventually become Gondor, correct? And the black numenoreans built strongholds farther south, notably in Umbar - before and after Sauron was taken to Numenor.

How much is known about the Numenoreans and their history in the South?

Thoughts?...