I've already tackled whether or not you really need to shut down your computer at night. If you haven't seen it, click here for my definitive answer.
One of the big reasons people don't turn their computer off regularly is that it's so slow to start up again. That's why other power-saving options exist that are faster.
I'm sure you've seen the Sleep and Hibernate options. But now Windows 8 also has Fast Boot and Hybrid Shutdown built in. And then there are high-speed solid-state hard drives that can make a big difference.
If your head is swimming at the possibilities, don't worry; it isn't as bad as you think.