I have my arc guide now, and I have my symbol. Am I ready to tween? Yes! But there's one more thing to explain: SNAPPING. You'll find snapping at times to be a big inconvenience when you don't want it to run, and at times, like now, it'll be very helpful. When snapping is enabled for objects and guides, as you move an object it will naturally gravitate toward the guide in question. Experiment with the settings from the View->Snapping submenu to get a feel for what each snapping setting will do. At this point I have snapping enabled for Snap Align, Guides, and Objects.