Answer:
I am so simple that I can only point. Yet I guide men all over the world.
My tongue hangs out as I run over fields and streets all day. I get tied up every morning and untied at night.
A dagger thrust at my own heart, dictates the way I'm swayed. Left I stand, and right I yield, to the twisting of the blade.
What do you have when you're sitting down that you don't have when you're standing up?
What grows in winter, dies in summer, and grows roots upward?
I have two eyes in the front and a lot of eyes on my tail