Watering tips for flower garden and a tree... what would you recommend?

Soil conditions vary, so a schedule based on time isn't appropriate. Just water enough to keep the soil moist, and when it is almost dry, water again. Most plants don't like to have "wet feet", so you don't want to overwater. Watering should continue throughout the first growing season, as it takes that long for the plants to establish their root systems. After that they should do quite nicely on their own, only needing watering during an extended dry spell.