I keep a log of every significant thing I read, and have done so for many years.  Now that I am back in school, I find myself reading broadly, beyond the textbooks, for my many required papers.  The system that I have adopted over the years is as follows:

The Date I finished reading the text

The Title of the text  (essays, short fiction, and plays in quotation marks)

The Author of the text  (I try to rotate authors as much as possible)

The Length of the text (in pages, or in lines for poetry)

The Publication Date

I then attempt to rate the quality of the text using a four-tiered system:

Two-Stars (for the very best books or pieces I encounter)

One-Star (for those I would recommend to literate friends)

Blank (for those texts which were just average and not particularly impressive)

X (for those texts sufficiently bad as to have no real redeeming qualities)