Help with nodes?

ok so basically im weedarted. I can smoke it but im having trouble understanding the parts of the plant which is pathetic because i've been growing for a month now. Can someone explain what the node is? i know there are internodes so how can you tell what the regular node is - shit im retarded. and when taking clones do you cut the branch off or the main stem going up like topping or w/e. Please send me a link to a site explaining with PICTURES!!!! thanks

Nodes are points on the stem where branches come out