Download & install notepad++ (you can use the builtin windows notepad.exe, but notepad++ is much more useful for editing FSO related files, like tables)
Create a new file, add the info, "save as" in the correct location. That should be all there is to it.
I'm not as familiar with adding ships, in general you need to:
1) save the .pof to data/models
2) save the textures to data/maps (IIRC)
3) add the table entries, either modifying the .tbl or adding a .tbm to data/tables
I *think* that's it? Assuming no modifications to the model are required...