Great question on how to measure your success in a 1:1 program. There are many aspects to consider, but starting with the end in mind with collaborative documents providing your vision and measurable student learning outcomes aligned with ISTE NETS and 21st century Skills is a staring point. Everyone needs to know why and how we will get there to measure the success of a 1:1, and the ongoing assessment and reflection piece is critical for documentation purposes.
Here are a few links of processes of how others are measuring sucesses and a few atttachments to craft your vision and measuarable student learning outcomes of a 1:1 program.
6 Steps to Building a Successful School Laptop Program: http://www.convergemag.com/edtech/6-Steps-to-Building-a-Successful-School-Laptop-Program.html
1-to-1 Laptop Program: Planning for Success: http://www.techlearning.com/article/32990
Research study on 1:1 from Dever, CO: http://scienceandtech.org/documents/Technology/DSST_Laptop_Study_Report.pdf
One-to-one computing programs only as effective as their teachers: http://www.eschoolnews.com/2010/02/16/11-programs-only-as-good-as-their-teachers/