Determine the water pressure from the supply source you intend to use for the sprinkler system. You can do this by shutting off all other water in the house, then by attaching a water pressure gauge and a hose bibb to the outlet to which you intend to connect the sprinklers. Turn on the outlet and note the reading on the pressure gauge. You'll likely need at least 20 psi (pounds per square inch) in order for the sprinkler system to work.
Remove the water pressure gauge from the hose bibb, and set a one-gallon bucket under the water outlet. Turn the water on full and carefully clock the how long it takes for the bucket to fill. Divide the number of seconds by 60 to get the gallons per minute (gpm) capacity of the water source.
Make a map of your property, marking the areas you want to irrigate and how much water they will require. Group each area into a specific zone, each which can be controlled by a single valve. This will ensure that each area receives the amount of water it requires.
Use stakes to mark the spots where you want to place the sprinkler heads and the valves. Every sprinkler head has a throw distance listed on its packaging: divide that number by 1.4 to determine how far apart the sprinkler heads should go. This will allow for some overlap and make sure the entire area is watered.
Then run a length of twine between all of the stakes. This will give you an accurate sense of where the pipe will be laid and how long each length of pipe needs to be.
Cut lengths of PVC pipe with a hacksaw corresponding to the lengths of twine tied around your stakes. The PVC pipe needs to match the size of the water outlet: usually either 3/4-inch or 1-inch.
Install the control valve manifold in a centralized location, near the water outlet you intend to use. Take note of each control valve's circuit. Divide the gallons per minute capacity you measured in Step 2 by the listed gpm rating of your sprinkler heads. The result is the number of sprinkler heads you can install on each circuit.
Install a control tee to the water supply you wish to use, then a stop-and-waste valve directly below the tee. You can use the stop-and-waste valve to cut off the water supply to the entire sprinkler system without stopping the water supply from any other part of the house.
Run a PVC pipe from the stop-and-waste valve to the manifold. Apply PVC solvent to the connection to ensure that the seal is tight.
Dig a length of straight trench alone the areas marked by the twine. The trench should be narrow and between 8 inches and 1 foot deep. It also needs to be as level as you can make it.
Lay down the cut PVC pipe along the trench, corresponding to the lengths you measured with the twine.
Attach PVC riser tees to the pipe in the trench, corresponding to the spots where you want the sprinkler heads to go. They should be at a 90-degree angle from the ground: use a carpenter's level to measure them.
Use PVC sealant to make the connections watertight once you have measured the risers properly. Wait at least two hours for the sealant to dry before proceeding to the next step.
Attach the sprinkler risers to the riser tees, treating the connections with PVC sealant to make them watertight. You may need to cut of small sections of the risers with a hacksaw to ensure that they are all of the correct height.
Attach the sprinkler heads to the risers and make sure that they are tight.
Set up the system controller in an appropriate location and run the electrical wires to the connectors on the control valves. Test the valves one by one to ensure that water is flowing through them as it should.
Refill the trenches and pat them down until the soil is level with the surrounding ground.
Program the system controller to turn the valves on at the times you wish to run your sprinklers.