Interlinking - when you post a text link inside a hub to one of your other hubs. example: article A complements article B so you want to link them together. Use the best 2 word text phrase in article A as the anchor text (the text that ends up being the link) and put in a link to article B. this should be article B's keywords or it doesn't help it at all.
An article should only point at the same article 1 time. So, one of your articles on changing has too many links in it. You only need one.
When you are backlinking then you don't want to interlink the same articles. Say you want to promote article B then you would put a link in article A but not a reciprocal link so that they are both linked together. That gives article B more "link juice" in the search engines.
When you backlink those articles that usually means that you are using a bookmark site or another site like InfoBarrel to write related articles and put a contextual link in it. The more backlinks that go to one articles the higher it can potentially rank. But make sure that the text you choose as your "anchor text" is a keyword.
I hope that's not too confusing! My profile page on here has a few sites that I use for backlinking, etc. if you want to know more. Hopefully that helped some though.