For an introductory book on numerical methods, see
Numerical Mathmatics and Computing, 6th Edition ,
by David Kincaid and Ward Cheney, Brooks/Cole: Engage Learning, 2008

For a more advanced book on numerical analysis, see
Numerical Analysis: Mathematics of Scientific Computing, 3rd Edition ,
by David Kincaid and Ward Cheney, Brooks/Cole Publishing, 2002

For an elementary book on linear algebra, see
Linear Algebra: Theory and Applications ,
by David Kincaid and Ward Cheney, Jone and Barlett Publishers, 2009

For software packages, see
NSPCG
ITPACK