The good feature about concrete pavers is that they are thick enough to be installed directly onto crushed stone and sand or just sand--as opposed to other pavers that must be installed onto a concrete pad. Laying out the area that will receive the pavers is as important as all other aspects of installation. When removing the soil from the area you are paving, consider the thickness of materials going back into the area--4 inches for pavers, 4 inches for crushed stone and 2 to 4 inches for sand, depending on whether you install crushed stone beneath the sand or not. The best way to install the pavers square is to install wooden stakes at the work area on four sides. The stakes will be driven in outside of the actual work area--maybe 24 inches. Attaching nylon string to the stakes should reveal a cross that meets directly in the center of the work area. Check the 90-degree angles in the center of the strings to ensure they are square. You can work in one of the four quadrants at a time when installing your concrete pavers.
When installing your concrete pavers, lay them on a bed of crushed stone and sand. Use a hand tamper to pack the crushed stone, but don't compact the sand, which must be installed over the top of the crushed stone. When installing the crushed stone, pitch the grade so that the pavers will drain water to one side. Use a rubber mallet to tap the pavers into the sand, and use a straight edge to ensure the pavers are evenly installed. Laying the straight edge on top of the pavers will show any uneven areas. Filling the joints of the pavers with sand will help hold the pavers together. Seal the pavers with a concrete sealer after the installation is complete.