Just because you're a newbie doesn't mean you can't give comprehensive c+c. Don't look at art as some technical thing that only when you know how to use photoshop and produce awesome signatures that you can then give good c+c.
Tell people what you think not how to use photoshop.. this saying, "i'm a newbie so i'm not going to c+c" is bullshit, just say oh it looks a bit blurry.. don't need to be some massive long paragraph about how to use gaussain blur.
It's better to develop your critiquing skills and your artistic skills by realising art isn't a bunch of technical words that you have to learn through scrolling forums and clicking on a program, if it's blurry say, if it doesn't look right, say. Thoughts?
( I guess this is more of advice, so read it.. but then give me your thoughts too )