Frameworks & Guides
SETT (Joy Zabala) This is a popular framework and eval tool; acronym stands for "Student, Environment, Task, Tool" -- understanding the first 3 will lead to the right tool.
Wisconsin Assistive Technology Initiative Assessment (PDF). One important point is "AT consideration" vs. "AT assessment".
Council for Exceptional Children's Assistive Technology Consideration Wheel An interesting info tool with definitions and legal language; quick guidance about AT in reading, learning/studying, math, motor aspects of writing, computer access, composing written material, and communication.
Virginia Assistive Technology Resource Guide (PDF)
Apps
From the recent (10/2012) QIAT listserv thread on evaluation: ATEval2Go