'A Survey of Modern Algebra' by Garrett Birkhoff and Saunders Mac Lane has a really good treatment of linear algebra. Anything particular that you didn't find clear in Boas' treatment, or the whole topic of linear algebra?
She uses vectors to find distances between planes and such. Example given a plane 3x + 4y + 5z she immediately says the vector perpendicular to this plane is such and such. I don't know how she gets that.
Distance between lines, planes, parametric equations et. al. are not too clear.
Matrices could have been done with a little more depth. The different types of matrices are over in a flash.
I suggest, if those are the difficulties, you get Stewart's calculus book from the library (DO NOT buy it!) and reading the relevant chapter(s) on vectors. For the matrices part, try finding a book on matrix algebra, which isn't quite the same as linear algebra. Perhaps something like these books (btw I have not read them):