I'm writing a book, but the problem is I don't know if I should end it in a cliff hanger. I'm really happy about my work but I thought if I ended it with a little mystery it would be interesting and maybe I could write a sequel? But I want to know if the readers like it first before I start the second book. Should I end it in a cliff hanger??
I also agree with Jonathan and Adrian - finish the story in your first book so it can be read as a stand alone work, even if you leave a couple of loose ends that can lead into the next book.
Also I have heard that it's far more difficult to sell a series as opposed to a single novel, as there is more potential cost in terms of printing etc for the publisher, so a complete single manuscript will be more appealing than one that leaves the reader hanging.
Good luck and I hope this helps!
If there has been resolution before the cliff-hanger yes, if not no. The reader needs to feel satisfied.
I agree with Jonathon.
Some loose-ends may remain for future novels as long as you resolve the main issues leading up to the final chapter/chapters. The outcome should address the main theme and the underlying tension throughout the novel. The last chapters should include whether the protagonist achieved his or her aims.
I hope that helps.
Good luck.