How to affix graphic LCD to PCB?
Usually LCD displays come in a plastic "cage" that has pins (more precisely, bumps - they are very short) on each corner of its back. The PCB has holes to fit in, but that's just to prevent the display from sliding horizontally on the board. The board is then attached someway (screws, etc.) against the case "top" which has a window for the display, a little smaller than it in each dimension, and that holds it in place. Usually there's no need for an adhesive or glue, which also makes repair easier; just the LCD ribbon is really mechanically attached to the board. But for hobby projects there's nothing that prevents you to do so.

There are other, less popular methods. Displaytech's "LCD Connection Methods" document has a few diagrams, but it's not possible to attach a file here in .pdf format. In a roundabout conversion method, it's now on E&amp;R's imgur account here, sorry for the low quality.