I've tried many different ways to track independent reading, and the creation of a reading contract has been most successful for me. Students complete the reading contract, selecting 2 books that they would like to read. 1 of the books has to be completed by a given date--and I typically had them write a reader's response once the book was due (not included). You review the contract with the class and sign off on each student's book choices. I met with students to discuss their book and/or check in at some point each week to make sure they were keeping track of their reading (I made their log a reading grade).
This contract will allow students to choose from 2 to 4 books to read, and they can include additional books, if they read more than the 4 listed. I found that this allowed me to keep track of my "super readers" reading (collecting the contract each month), and also kept my more reluctant readers accountable for their reading each night.
Included here is the actual contract, with fill in the blanks, as well as a sample contract to show how I set mine up. It's really pretty simple to use for teacher and student!