“Some people feel links off a page drain PageRank. Others more accurately say it means that the more links you have, the less powerful each of those links are, i.e., if you wanted to boost another page, linking to it from a page with fewer links on it means each of those links should carry more weight. But it’s even more complicated than this, and the best advice for a site owner is to simply link out to any pages they feel a user
will find appropriate.” Danny Sullivan
Anyhow, the best practice is to keep your outgoing links less and very relevant, so that both search engines and readers should get what you intended to deliver to them.