This desk is fully assembled right out of the box!

The desk is 35" wide x 24" deep. It adjusts to any height from 6" up to 19.5" high. The keyboard shelf measures 27.5" wide and 11.5" deep. The desk can support 55 lbs. of evenly distributed weight. 

Attached please find the manual.

Here is a great video on raising and lowering the desk