Hello and welcome to Android Forums. Hopefully I can help you with your problem.
The best advice I can give you in order to avoid bricking a device is to read everything available pertaining to your device, flashing a recovery, rooting, and flashing customs ROMs.
As with any modification you do to a device, bricking is ALWAYS a possibility. Please keep that in mind and follow all instructions completely.
One of the main features that will helps you avoid a hard brick is to install a custom recovery such as CWM or TWRP. If you plan on modding your device, these are mandatory in my opinion.
Most of the higher end Samsung devices also offer Odin. I would suggest looking into it. It has helped me save several of my Samsung phones.
One more thing I would like to add concerning your issue. If you didn't do anything to your device and it just quit working properly, there is a very good chance that you experienced hardware failure. If the device is still under warranty and the device will not boot up, there may be a good chance that you can contact Samsung and they many fix it for you. It's worth a try. The worst thing they can say is no. IMO it's worth a try.
If you have any other questions regarding your device, I invite you to join Android Forums. We have many sections for specific devices which contain a wealth of information.