"Dream Guide" is more of a loose term in my opinion. It really depends on the dreamer. Some people have multiple dream guides, some have only 1, and some have none. Dream guide is a term used for a DC who helps you obtain lucidity, or teach you the ways of the dream world. You can make your own dream guide if you want to. Alot of dreamers just happen to find a reccuring DC who often helps them with lucidity/lucid activities, and they dub him "Dream Guide." I have only saw my dream guide once, and it was the very first lucid I had after joining Dreamviews! They can be a good thing to have, because they often show up in normal dreams, which can cause you to become lucid. They can also help with tasks/actions that you wish to perform within your dream.