Not sure what feedback you should give?
If you're a little stuck on the feedback you should be giving, or are not sure on the way a critique should be done, then I'll give you some basic tips here. You are also free to do a search online for: How to critique fiction. This should hopefully prepare you for how your work will be assessed and what other's will expect from you
This is a basic outline of what to do.
1) Introduce the work you are about to critique. First state the title, genre if known, and similar info, then a short one to two sentence summary about the story.
2) This is where you state your arguments about the story. Create a few points about whether the author got across their idea/point. If it was entertaining and kept you involved. If the story drifted or stayed on point. Cite some examples from the book so the author and other readers understand your point better. Was the dialogue realistic? Did you believe the characters were real? Was grammar or punctuation an issue?
Try to keep each point or argument in its own paragraph so the author and other readers stay focused on what you are trying to point out.
You are allowed to give your opinion and you are allowed to say what you like and don't like. However, please don't be nasty about it, and also say why you were not entertained (or were entertained) or did not like it (or liked it).
3) The last part of your feedback is to create an overall opinion of the piece. Sum up your thoughts and what the writer has achieved or needs to improve.
If you wish to read a good book on editing, then check this out:
Once you know how to critique, go to the "Projects to Critique" page to start giving feedback and to read the instructions on where to send your critique.