Links that send users to other domains from your site are outbound links. By linking out to domains related to your page you increase quality and trust in your site. In turn, it helps the search engines understand the niche of your site. Outbound links give a clear idea to search engines about the topic of your sites and help to build relations with relevant and related pages in your niche.
According to Google linking out that's natural and valuable to the user is good practice.
"Well linking to other websites is a great way to provide value to your users. In the most common cases however if you're linking out naturally from your content to other sites that offer additional value and more context. Then that's fine and there's nothing special that you need to do." John Muller, Google
Muller mentions that certain types of link like link exchanges, sponsored links and site comments are not good SEO practices.
"I would watch out for a few types of links though. In particular if you're linking out to a site because of an arrangement, like you linked to me and I'll link to you. Or because it's an advertisement." John Muller, Google
When you produce outbound links, ensure you are not linking to private blog networks. The Google Panda update has devalued their links and is shutting these down to avoid two-way backlinking.
Keep the focus of your links on sites that are related and relevant to your niche. By linking to these sites, you will be able to target visitors interested in the topics of your site. Outbound links can increase your credibility especially when you link to trusted, high SEO ranking sites with a good domain value.
To keep your site easy to read, avoid using too many outbound links. It is better from the perspective of the viewers. Another strategy is to focus on internal linking predominantly and then link out to relevant blogs but only a few of them. Ensure that your content is useful and you present accurate information about your topics.
To get targeted traffic to your website, it is important to use the reciprocity system. If you refer to another individuals page in a page or guest blog of yours, and it is relevant to your topic, ensure you include a link to their page. By doing this, it will improve your content and will allow the opportunity for a reciprocal link exchange.
You can learn more about Inbound Links here.