Generally, as long as you only copy a portion of the content, and give the proper credit for it, you won't run into issues. What I would do is quote part of the article, and provide a link to it for anybody wanting to read the whole thing.

If you copy content you can get penalized by Google and others search engines. What you can do is to recommend that blog post with a link on your blog adding a few sentences on why you are recommending it.

If you want to take content from another blog make sure you quote them, and usually provide a link back to their original content. I often do this to make a point and then drill down further.

Do not take their content as the entire post without adding further to the thought, that would definitely hurt your Google ranking since the majority of the content already exists elsewhere (and they had it first).

Most blog software will also send them a ping (post about your post) when you include a link their original topic. This also will help drive traffic to your blog.

but how do u give them credit?