You have just bought an expensive, you must need to understand well on the device to optimize its performance and make it to be your super smartphone ^^. I bought the Galaxy S3, so understand the hardware and software features is a must to me to share more “hidden” features and findings to you. Thanks to Samsung who provides the complete user guide for their users to know all and most of the hardware and software features in Samsung Galaxy S3. Different Mobile carrier has their own user manual for their customer due to different hardware specification on Galaxy S3. See below 3 different user manuals  for SG3 international, T-mobile and Verizon version.

User Manual For SG3 GT-i9300 International Version [Download]

User Manual For SG3 SGH-T999 T-Mobile Version [Download]

User Manual For SCH I535 Verizon Version [Download]