Hi guys, I have read through some threads on here (but of course I could not read through them all) and I hope that I will not be repeating what was already asked. I would like to get writing, I have been walking around for some time with some scenes and an idea in my head - if you will - and i want to try to maybe put the "idea" in a book. I understand that an idea is probably not enough to have a book, but maybe if I work on it, it can turn into something.
I have reading through the plotting and some exercises, but my story (so far) does not quite have a designated antagonist.
I want to write a book a book from the point of view of "the other woman", basically an impossible love story about 2 people crazy in love but prisoners to circumstances - both are married. The more general idea that i want to demonstrate is that "the other woman" also has feelings, and love is not quite so black and white sometimes.

Any ideas, views as to how i should proceed, what i should start with - I would highly appreciate it.

Thank you,