Vimal Dhruv explains the importance of setting the base point of your files in AutoCAD.
"When you use the Insert Xref command, it will ask you for an insertion point. Often, the drawing which you are inserting is not inserted where you expect it to be; it may appear anywhere in the current drawing. Then you have to move that inserted drawing to place it at the proper location.
"We have two very simple solutions for this problem. First, whenever you create any drawing, make sure your insertion point of that drawing is at 0,0. (By default, the assumed base in AutoCAD is at 0,0,0.) Second, you can draw your drawing anywhere, but after you finish drawing, issue the Base command and select that point from where you want to insert your drawing."
Notes from Cadalyst tip reviewer Brian Benton: The base point in a file, by default, is set at coordinates 0,0,0. As long as you keep your linework relative to those coordinates throughout your project, your files will line up perfectly. Many times, however, we draw with no regards to the coordinates, and that’s fine. Use the Base command (type Base on the Command line) to establish where 0,0,0 will be in your drawing.