After 9 years of writing Ruby on Rails code, link_to() never ceases to trip me up. Does it trip you up, too? Here are some quick notes:

1. The first argument is what you want inside the <a> tag. For example link_to("today's news") produces <a>today's news</a>
2. The second argument is the href attribute value. For example, link_to("today's news", "www.news.com") produces <a href="www.news.com">today's news</a>
3. The third argument is a hash that contains everything else – most importantly, your <a> tag attributes. For example, link_to("today's news", "www.news.com", {id: "newsbox", class: "infos"}) produces <a id="newsbox" class="infos" href="www.news.com">today's news</a>. The third argument can contain many other options, of which I have never been able to find a definitive list.