Resources for IRT/Rasch Modeling
Books and Articles:
Harris, D. D. (1989). NCME Instructional Module: Comparison of One-, Two-, and Three-Parameter IRT Models. Educational Measurement: Issues and Practice, 8(1), 35–41.
Rasch Software:
Rasch Measurement Analysis Software Directory
R + the eRm package
Mair, P., & Hatzinger, R. (2007). Extended Rasch Modeling: The eRm Package for the Application of IRT Models in R. Journal of Statistical Software, 20(1), 1–20.