I am looking for a way to move the timeline a specific amount, scroll, etc. even if the Timeline window is not open. Is this possible?
→ 1 frame forward
← 1 frame backward
Shift+→ end frame
Shift+← start frame
↑ next keyframe
↓ previous keyframe
⎈ Ctrl⇧ Shift→ next marker
⎈ Ctrl⇧ Shift← previous marker
Shift+↑ 10 frames forward
Shift+↓ 10 frames back
Hold down the Alt button and start scrolling the Mouse Wheel.
Scrolling down will let you go forward in a Timeline, scrolling up works vice versa. You can do it in almost every window type you want and it works even if the Timeline window is not open.
(I know this is an old question, but I got here while looking for an answer. So, just for the record...)
You can change the size of "steps" (or "jumps") Blender does (when pressing Left/Right, Shift + Up/Down, and even Alt + Wheel/Scroll) by changing the "Delta" parameter in the shortcuts "Frame Offset".
Path: Blender User Preferences > Input > search for a shortcut named "Frame Offset". Then change the "Delta" value to whatever you want (default is 10).