As part of a military site, I do this very thing quite a bit. Am not familiar with newspaper articles, but for other things as copying or using others content, all that is usually required is an email asking for permission.
1. When asking for permission to use a portion of an article or reference an article or information, I tell them exactly what I want to use, where it is found on their site, (Most times, they don't know where to find the info on their site

, what I want to use it for, what type of site I have. I also offer to link back to their site from mine, and offer up their copyright or credit notices.
2. In some cases of late, some sites have asked that I write up their content as it will appear in my site, and give them a chance to review it prior to publishing. (I always give them the option to review the draft and make any changes they wish).
3. I have never had to pay for use of someone else's content
4. I keep meticulous records (Notebooks full) of emails to and from and of permissions granted and/or permissions denied. In over about 6 years or so, have only been denied use less than a half dozen times. (The one major exception is that was denied use of content on a free website, because the author didn't like the smoking banner ads). Once I went to a paid host, I again asked for permission and was granted same.
5. Still as with most things, other authors or sites, don't want you copying entire content from their sites. They are usually OK with a paragraph here or there, or several, but not pages upon pages.
6. You can always look up two or three sites on the same subject, then draft your own version. Don't copy exact phrases, but try to come up with your own version of the same material. (I do this quite a bit. It is painstaking work, but after a while, you'll get the hang of it).
7. I'm not sure how newspaper type articles would handle such things. I suppose you could make a deal, to have them feed their content to your site via some feed method. I'm not up to speed on this, but others here may be able to help you this one. My slight experience with newspapers is that they are pretty uptight on use of their copyrighted material.
8. My last try at this, I wrote an article about streetcars and referenced an article from our local paper. I quoted a sentence or two from their article, put it in italics and quotes, then referenced the article at the end of my article under Sources/Credits/Copyrights. You can also add a MORE tag, to send your readers to the exact article.