After this time, the energy needed to run the computer outweighs the start-up energy. A modest amount of turning equipment on and off will not harm the computer. The life of a monitor is related to the amount of time it is in use, not the number of start and stop cycles. Try to plan your computer-related activities so you can do them all at once, keeping the computer off at other times. Do not turn on the printer until you are ready to print.
Printers consume energy even while they are idling.
If you spend a large amount of time at your computer, consider reducing the light level in your office. If your computer has these features, make sure they are implemented. That, however, is the only thing they save. Instead of saving energy, screen savers that display moving images actually cause your monitor to consume almost as much electricity as during active use. Since these programs involve interactions with the CPU, they require even further energy consumption.