The Adirondack chairs are very easy to assemble.  The instructions recommend that 2 people work together.  However, I found that I could do it myself without any assistance. The instructions are very easy to understand and the pieces can be assembled on the floor in about 20 minutes.  
Once fully assembled and positioned where you want them to be,  the chairs are extremely comfortable.  I honestly did not want to get up after I sat on them.  I would definitely recommend these chairs and would buy more of the same.