Before you water your sago palm, be sure that it is on a well-draining slope. No, it doesn't need to be on the top of a mountain, it just needs to be where water will drain and it won't stand with "its feet wet". If your sago palm is in an area that collects water, whether after you water it, or after it rains, the roots will rot and the plant will die. I have killed sago palms by overwatering, but by no other way.
But sago palms are not cactuses. They do need water to be their best! This is what I have discovered:
Water them in the summer every day. I have a simple battery-powered timer that comes on every day for fifteen minutes. That's the summer schedule. And since all of my cycads are planted on well-draining slopes, I can be this generous with water without having to worry about the roots rotting. The plants take all they need, and never get too much. Even during the summer thunderstorms, they won't get too much water.
Don't water them in the winter. From November through February I turn off the watering system here at The Tropical Paradise. If I have flowers, etc., that need more water, I water by hand. I have a hose nearby and I have a nice big lightweight plastic watering can.
And there you go. Keep in mind that sago palms, like all cycads, only grow in the summer, usually only one burst of growth called a flush. Sometimes you will get two, but that's rare. And always in late spring and summer. So give them water then. You can give them dry plant food (I like to use the houseplant spikes I get at the dollar store) and hand-water the leaves with a water- soluble plant food like Miracle Grow. And, yes, only in the summer.
When your winter visitors start arriving, pay attention to them, and ignore your sago palms. If you've done everything right in the summer, they will be gorgeous all winter.