I’ve heard people talk about these but I have no idea what they are or how to find them. Can someone explain?
The “Search” button can be your best friend.
A dream guide can be multiple things, ranging from a dream-time companion to a spiritual, astral, other-worldly guardian. Usually he/she/it is only found by you, after analyzing dreams or meditating.
Some people equate the dream guide with the spirit guide, which exists beyond dreams, and of which there are many more topics to investigate.
Meeting Your Spirit Guide While Awake
Off-site spirit guide resource
DGs are pretty neat. They can be anything from a friend to a helper in dreams. Say you have trouble with flying, ask yours for lessons and he can help. They don’t always have to be a human, either. They can be an animal, alien, or even robot.
Lots o’ fun. 
Check out the topics around the forum. The “Search” button is right under “Welcome to LD4all” with Home and Profile and whatnot.