Books and Writing

I am trying to decide if I am going to re-write what I have for my Mage Novel so far. I have been rolling the plot around my head for the last week or two and have decided I can either wrap it up and end it now or re-write it as a series.
I am really leaning toward the series. I would be able to follow my character as she ages and grows and that would be a lot of fun ( and a lot of work). I am looking for a book on World Building. I need to figure out how other lands and courts outside of the one she is in operate and who is fighting who, ect…
I am tempted to do both, wrapp the novel up and write it as a series…Just to see which works better. Might have to play and see what happens.