KRHolbrook's Reviewing Guidelines

Before you begin reviewing someone else's work, remember that their style will differ from yours, so don't go editing their work to match your own.
Point out what you liked somewhere within your critique. While making adjustments and criticism to an author's work is wanted, not all writers have a thick skin.
If you critique as you read, tell the author so. Also tell the author if what you're reading isn't normally in your to-read queue. (For me, this would be sci-fi--something about it just doesn't much hook me, but I'll still try to give it a read.)
To add on to that, if you're unable to continue critiquing the work, note the stopping point and explain why to the author.

Short Stories & Novels

Characters:
Does the character have a name?
          If not, do you feel they need one?
          If more than one character, do the names sound too similar and confuse you?
Is the character's goal clear?
          Do they stay on task with their goal, despite obstacles thrown their way?
          Is it clear how they meet their goal in the end?
Does the character's personality remain the same?
If the character has a background, does it fit who they are now?
Does the character have a clear description?
Does the character speak properly?
Do they seem real, or have a cardboard cut-out quality?
Did the character(s) seem too cliche?
Is there enough emotional conflict when there needs to be? (Such as romance stories.)
If more than one character, are they each different and can stand alone, or do they mimic the styles of each other?
Is the opposition pushing the main character to their limits?

Plot:
Does the story move too slow?
Did the story start at the right place?
Did the story end at the right place?
If there are subplots, do they feel disconnected?
Does the story confuse you in any way?
Do you forget about certain characters while reading, specifically the main one?
Are you bored with the story?
Does the plot present enough obstacles for the main character(s)?
Does the action escalate with time?
If it's a chapter, does the chapter as a whole advance the plot forward?

Setting:
Do you understand where the story is taking place?
Was there too little or too much description?
          Did you skip the descriptive areas because they were too boring?
If it's a different era, do you feel the descriptions and actions of the characters fit this time frame?

Point of View:
Are there too many points of view in a story?
Does the author stick to one main point of view for each chapter / page break?
If the story shifts from one PoV to another, is the transition smooth or choppy?
Does the author use the same PoV the whole way through, or do the mix and match (poorly)?
Did the author's PoV seem right to you?

Show vs Tell:
When in a character's PoV, are your senses active (smell, sight, touch, sound, etc.)?
Are the character's actions described?
Do you feel the author at times is "holding your hand" through certain events, instead of letting them flow naturally?
Are there colorful descriptions, or the dull kind (aka "very", "really", "great", "nice")?
Does the writing sound like a lecture, or does it draw you in with action?

Grammar and Spelling:
Do the sentence lengths vary?
Does the author use short sentences for tension and longer sentences for a relaxed effect?
Do the paragraph lengths vary?
If there are sentence fragments, are the misplaced, or feel natural where they are?
Does the author properly use em dashes, semicolons, commas, quotations, and other such punctuation properly?
Was the story readable?
Does the author capitalize the correct words or are they random?
Does the author use too many of a specific thing (adverbs, explanation points, he said, she said, etc.)
Were there too many cliches?
Was the author's writing too dramatic?

Poetry

On Poetry:
Is the subject of the poem clear?
Does it read smoothly, or is it jilted?
Is there too much repetition of something that makes it feel redundant?
Do the line breaks seem natural?
Are some words too weak for the point of the poem?
Is there a constant pattern between syllables / meters, and if so, does the poem stick to that rhythm?
Does the author remain consistent with specific punctuations throughout the poem?
Did you find any cliches?