Added new bibliography sections and links

After an e-mail exchange with Erik Bray on whether there is a collection of links to articles etc (that instructors may want to draw upon during their boot camps) I've added my set to the bibliography page under the headings "Blogs", "Hints, tips, advice and cautionary tales" (links to specific blog articles, news items, and other things), "Humor with a point" (lighter-hearted links e.g. cartoons and animations but which may make valid points).