This is from an answer I recently did. You can check it out here
To create a po file with poedit, follow the following steps. Please note that my poedit is in Afrikaans.
Open poedit and select the option to create a catalogue. The following screen will appear
Fill in the required fields as shown.
Now click "Sources paths" tab and complete as shown. Use
. in the "Paths" field if your language file is in the main directory, and use
.. if the language file is in a folder like language
Now click the "Sources keywords" tab and fill in as shown.
Now save the poedit file as
en_US.po in your languages file. It is important that you save the po file directly in the location where it must be, otherwise it will not work. Poedit will now search and add all strings for translation to your po file. A mo file is automatically created when the po file is saved.
At the end, your po header should look like this
"Project-Id-Version: Transparent v1.2\n"
"POT-Creation-Date: 2014-03-12 16:25+0200\n"
"PO-Revision-Date: 2014-03-12 16:28+0200\n"
"Last-Translator: Pieter Goosen <email@example.com>\n"
"Language-Team: Transparent <firstname.lastname@example.org>\n"
"Content-Type: text/plain; charset=UTF-8\n"
"X-Generator: Poedit 1.5.5\n"
"Plural-Forms: nplurals=2; plural=n != 1;\n"
For further reading, check this tutorial. It really helped me when I started on translations. Hope this helps.