polyglot:
Most watering solenoids are 24VAC and about 100-300mA, so you need a big 24VAC transformer
Would this transformer work?
polyglot:
you can probably buy an 8-relay shield ready-made for the arduino.
Would this 24V 8-relay shield work?
http://www.nyplatform.com/index.php?route=product/product&product_id=760
Also, is an Arduino Uno beefy enough for this, or will I need a something like the Arduino Due?
I appreciate all the information you've give me so far, any more details and or insight on how I would go about doing this would be helpful.
Sean