Carpet tiles are easy to install. It is best to start in the centre of the room, lay out a cross in carpet tiles and then adjust its position to avoid uneven or very narrow gaps around the perimeter.
Do not start against a wall; if the wall runs out, so will your carpet tiles. Once you are happy with the position of your starting cross, fill in the four quadrants and do the perimeter cuts.
Adhesive will stop the tiles from slipping or moving, but will allow easy replacement of necessary.