Finished the book, what now?

Hi all,

I've got to the point where my book is finished, I just need to tighten it up and then it's ready.

But where do I start looking to get it published? Should I focus on relevant agents, try and find publishing houses that accept unsolicited manuscripts (if any?), or look into it getting self published as an ebook? Where would I look for that?

I realise this is a big question to ask, but if anyone has any advice at all they don't mind sharing that would be great!