http://www.amazon.com/Geometric-Algebra-Physicists-Chris-Dor...
Once you get an intuitive grasp of bivectors, it's not hard to "see" tensors as a linear map of bivector into bivector.
Geometric Algebra for Physicists is very clear and gently paced. http://www.amazon.com/Geometric-Algebra-Physicists-Chris-Dor...
This one also looks good: http://www.amazon.com/Linear-Geometric-Algebra-Alan-Macdonal...