I am very selective about which sites are linked to here. To get a link here a site needs to be a quality one with content that is relevant to and compatible with the content and 'message' of at least one of the main sections of this site (if necessary I'll create a new section for it here). Further, the site needs to have clarity and focus, without distractions, being reasonably clear of distracting 'cleverness' or ads / popups.
Very many sites try to be far too clever in their design and are hard to read or/and fail to have proper focus on their content because of all the distractions (especially unnecessary graphics, animations, and strongly coloured backgrounds for text). I do not want to link to sites like that, however worthy the intentions of their owners. The site's text (all of it) also needs to be clearly legible, and that means not only none of the aforementioned distractions but also a proper contrast between text and background, both in tone (degree of lightness / darkness) and in colour. Just shades of turquoise or shades of brown, for example, is immediately difficult to read, as well as being unpleasing to the eye, and some thought needs to be given to the use of complementary colours.