First have someone else check with the RI well regulators to see if you need a "Well Construction Permit" to install your own "Sprinkler System Well". If you don't great, if you do it's up to you whether you get one or not. If it's not a drinking water well there may be no problem. That's the reason to have some one else check on the regulations! Check here http://www.dem.ri.gov/programs/benvi...well/index.htm
If everything is OK, I suggest you go to Lowes or pumpsandtanks.com and purchase some 2" Schedule 40 PVC; reducers from the 2" PVC to your garden hose on one end and using a 2" PVC Coupling on the bottom end. Cut saw type teeth on the bottom of the coupling and glue it to the bottom. Turn on your garden hose and push the 2" PVC in the ground while rotating clockwise and counter clockwise 1/4 turn where you want the well. Keep in mind the State Regulators will require a specific distance from buildings and possible contamination sources such as ponds; septic tanks; leach fields; out houses and sewer lines. This is usually 10 feet to 50 feet. Know the rules! Continue washing the 2" in the ground until the water from the garden hose stops returning around the 2" PVC. Once this water stops returning, you may have encountered a water producing zone. At this point I suggest that you either remove the 2" PVC from the hole or better yet leave it in and cut it off about a foot above ground (for drilling/washing deeper if necessary). Purchase a 1-1/4" by 3' to 5' steel sand point and enough galvanized pipe and drive couplings to reach the bottom. Place a drive cap on the top joint and hook an old tire over it, them with a sledge hammer drive the sand point at least another 3' to 5'. Fill the 1-1/4" pipe with water and it it goes away you probably have a well. Hook a pitcher pump to the 1-1/4" pipe, prime it and pump. If it pumps water you have a well it not check for leaks and do it again. If you can pump water you have a well. remove the pitcher pump and install a "Shallow Well Jet Pump" with a small tank to make an automatic system. You can purchase a 1/2 to 3/4hp pump from Lowes or from www.pumpsandtanks.com. Pumps and Tanks will be able to assist you by email. Lowes knows nothing about pumps, they only sell!
To to the following for further assistance in driving wells http://www.lifewater.org or http://www.lifewater.org/resources/rws2/rws2p2.pdf
Once you have the well completed I recommend that you seal around the 2" and between the 1-1/4" and the 2" with bentonite from a well supply house or possibly from www.Pumpsandtanks.com to prevent contamination.
Well Drilling is not just a hole in the ground! Good Luck!
For further information check www.dci-inc.us