You’re in luck the same kind of content appeals to both human visitors and to search engines that send you human visitors, so this is easily answered. You need content that’s original or unique (never paste in other people’s content search engines penalize for it, and your visitors will find it boring, besides the obvious copyright issues). You need content that’s relevant (to your industry or your locale). You need content that is updated frequently (e.g. blogging or treating your site much like a blog).
