There is always some level of danger linking between domains that you own, however, it is perfectly legal to do and something that should be done. Where Google draws the line is debatable though a lot is understood.
Know that no matter how hard you try, Google will relate your sites using a semantics database. That is inescapable short of some extraordinary means. So know that Google will be looking at both sites and not one or the other in many regards.
But do not let that scare you. Many people have more than one site.
Be that as it may. Google will look at link patterns to determine if you are trying to influence the SERPs. However, with just two sites, I am fairly sure you will fly under the radar for much of it. Still, if linking between the two sites are not done in a natural way, as anyone would normally and reasonably do, then the danger is very real.
What you do not want to do is any site-wide linking which are often found in headers, footers, and sidebars. As well, you want to keep your links as natural as possible and a bit sparse. Do not go crazy linking every page using keyword centric links. Make sure that each link is appropriate and conversational and that the topics of the linked pages are compatible. It is best to link within content using a sentence or partial sentence with at least a semantic subject, predicate, and object. This would be something like: Find out more about how Apache Tiki interacts with Apache Solr. where Apache Tiki is the subject, interacts with is the predicate, and Apache Solr is the object. There are many other semantic clues in this sentence such as the use of the word how, but let's leave it at that for now.
Since it is common that many sites are news and blog sites, perhaps it is best just to avoid the whole issue and make just one site. It is far easier to make one site rank and perform well than to divide the effort. It has been my experience that this could become messy and some level of duplication will arise. Just my 1.27 shillings worth.