Auto Power-on & Shut-down is a lightweight app that might be easier to use than taking a more DIY approach, e.g. creating scheduled tasks in Windows. For more info on the company, maybe check the certificates for info & Google -- the software's .exe files are signed. The biggest impact from installation may be the Windows file, C:\hiberfil.sys, which is added if it wasn't there already from having hibernate turned on in the past -- I mention it because some will notice this new, usually several GB file.
I like that the first time it starts Auto Power-on & Shut-down asks if you want to test your system. Some systems won't sleep, or won't come out of hibernation etc. Sometimes it's bugs in the chipset or bios, sometimes it's a fault in the engineering, sometimes it's hardware designed for an earlier version of Windows. Regardless, if you don't use sleep or hibernation now, test it 1st before you add something like this.
As far as putting a system to sleep or hibernation goes, some say yes -- some no. Your PC/laptop will waken faster than it will start from a cold boot -- how much faster depends on your hardware, security software etc. Many people don't mind if starting Windows takes a moment or two. There are advantages to turning a system completely off -- you don't have to worry about exploits or mal-ware waking the system up, you have less to fear from power fluctuations & spikes, in theory many electrical components don't age with use, but most people's experience suggests otherwise, & if saving electricity is good, saving a bit more must be also.
The opposing view is that cycling a system on, whether from cold boot or waking it up, shortens the lifespan more than you gain by shutting the system down or putting it into sleep or hibernation. Things like circuit boards, the components mounted on them, the mechanical parts in a regular hard drive, all expand when they get hot. That tiniest of movements in electronics, & the very real & measurable, though still tiny difference in say hard drive bearing clearances, does add some amount of wear & tear. Many businesses leave their computers on 24/7, whether they're doing anything or not, whether there's anyone in the building or not.
Regardless whether you leave your PC on 24/7 or use hibernation, the last few generations of hardware are going to use a lot less power anyway, by going into a lower powered mode whenever you're not pushing it, whenever you're not doing something that takes the full processing power your PC/laptop can deliver. Putting your PC to sleep just isn't going to make as big a difference in power consumption as it used to when the concept was 1st implemented years ago, I *think* with win98 if I remember correctly. If you want to actually measure power use, pick up a Kill A Watt [or similar] -- they run around $20, plug into the wall socket, & you plug your PC or TV or whatever into the device itself, & it tells you how much electricity is passing through it, i.e. how much that device or appliance is using.
http://www.thewindowsclub.com/wake-up-computer-from-sleep-windows
http://www.howtogeek.com/119028/how-to-make-your-pc-wake-from-sleep-automatically/
.