Hibernation was originally created mostly for laptops. When on the go it is helpful to be able to stop operation and pick right back up again without having to do a full shutdown. Since the laptop is technically powered off during hibernation this shouldn't result in data loss or hardware damage (like it would to carry the laptop running, a very bad idea). However, this is something that you are going to have to test on your laptop to see if the function works properly.
I have used an HP laptop with Vista for about a year and found that it did not handle hibernation well at all. When it went into hibernate it almost always froze coming out of it. When it didn't freeze it took nearly three times as long to come out of hibernate as it did to reboot. So in this case it was much more advantageous to just shut it down normally--so I set the power button to just shutdown.
However, this was probably largely due to the age of the laptop, it's weak hardware specs, and incompatible drivers. I would conduct a little test with your laptop to test whether you want to use the hibernate feature. Boot your computer up and open up some applications you normally use. Grab a stopwatch and then restart the computer, timing how long it takes. Do the same with taking it in and out of hibernation. There should be a significant difference in time but depending on the speed of your computer it may be more pronounced.
Then it is simply for you to decide: is the extra wait-time on bootup worth not having to reopen what you were doing? If you are the type of person who needs to access their computer quick, such as a college student needing to quickly take notes for class, it might actually be quicker and easier to do a full shut down.
My general suggestion is this: if you have the powerful enough hardware on the laptop and it doesn't run into conflicts with drivers, go ahead and use the hibernate feature. If not, you are far better of staying away.