ENVI tutorials are available online.

Contents of tutorials:
Introduction
ENVI Quick Start
ENVI Tutorial #1: Introduction to ENVI
ENVI Tutorial #2: Multispectral Classification
ENVI Tutorial #3: Image Georeferencing and Registration
ENVI Tutorial #4: Mosaicking Using ENVI
ENVI Tutorial #5: Vector Overlay and GIS Analysis
ENVI Tutorial #6: Map Composition Using ENVI
ENVI Tutorial #7: Introduction to Hyperspectral Data and Analysis
ENVI Tutorial #8: Basic Hyperspectral Analysis
ENVI Tutorial #9: Selected Mapping Methods Using Hyperspectral Data
ENVI Tutorial #10: Advanced Hyperspectral Analysis
ENVI Tutorial #11: Hyperspectral Signatures and Spectral Resolution
ENVI Tutorial #12: Vegetation Hyperspectral Analysis Case History
ENVI Tutorial #13: Near-shore Marine Hyperspectral Case History
ENVI Tutorial #14: Multispectral Processing using ENVI’s Hyperspectral Tools
ENVI Tutorial #15: Basic SAR Processing and Analysis
ENVI Tutorial #16: Polarimetric SAR Processing and Analysis
ENVI Tutorial #17: Analysis of DEMs and TOPSAR
ENVI Tutorial #18: Introduction to ENVI User Functions
» Read more: ENVI Tutorials are Available Online