Watering can be the biggest task during late summer, particularity if the weather gets hot. Vegetable gardens, most flowering plants, and the lawn all need about one inch of water every week to keep them green and looking nice.
Be sure to water thoroughly, and deeply each time you water. When possible, water in the morning or early afternoon so the soil has a chance to warm up before the cooler evening hours set in this will lessen the chance of developing fungal root diseases. Deep watering will induce the plant's roots to grow deeper, where they are less likely to dry out, as well as the added benefit of anchoring the plant into the ground better. Light, surface watering actually wastes water, because the water never actually reaches the root zone of the plant, and the moisture rapidly evaporates from the top inch of soil. The best way to tell if your plants are receiving enough water is to dig down a few inches. The soil should be moist at least 3 or 4 inches deep to insure that the water is reaching the root zone of the plants. Of course, if you planted drought resistant plants in your garden, you won't have to water as often, but the principal of deep watering still applies.
Be sure to check the hanging baskets and container grown plants every day during hot weather and about every second day on moderate summer days. Don't just check the surface... Push your finger an inch or two into the soil to be sure there is adequate moisture below throughout the root area. Water them thoroughly each time you water, but be careful not to overwater them.