[Swelsh620]

I am new to flashing roms. I plan on flashing my first rom using the internal storage method, but have a few questions. I want to make sure I am going to be doing this correctly. First I unlock the phone. Second I download the rom and install the .nbh file into internal storage root directory then change the file name leaving off the .nbh at the end as this will be automatically added. Third, restart the phone. And hopefully all goes well. My other question on this issue is does the original rom remain on the phone, and if I do not like the new rom how do I go back to the factory rom. Any help will be greatly appreciated.