You may find the following books useful to refer to if you need information on the methods used to check members in Steel Designer.
Manual of Steel Construction, Allowable Stress Design
American Institute of Steel Construction, New York, 1989, 9th Edition
Manual of Steel Construction, Load & Resistance Factor Design
American Institute of Steel Construction, New York, 1986, 1st Edition
Steel Buildings, Analysis and Design
S W Crawley & R M Dillon, John Wiley & Sons, New York, 1984, 3rd Edition
Structural Steel Design, LRFD Fundamentals
J C Smith, John Wiley & Sons, New York, 1988, 1st Edition
The Behaviour and Design of Steel Structures
N S Trahair and M A Bradford, Chapman and Hall, London, 1988
Australian Standard AS4100-1990: Steel Structures
Standards Australia
Australian/New Zealand Standard AS/NZS 4600-2005: Cold-formed Steel Structures
Standards Australian and New Zealand
Design of Cold-formed Steel Structures (to Australian/New Zealand Standard AS/NZS 4600:1996)
G. J. Handcock, Australian Institute of Steel Construction, Sydney, 1998, 3rd Edition
New Zealand Standard NZS 3404-1997: Steel Structures
Standards New Zealand
Steel Designers Handbook
B.Gorenc, R. Tinyou and A. Syam, UNSW Press, Sydney, 1996, 6th Edition
Design Capacity Tables for Structural Steel. Volume 1: Open Sections
Australian Institute of Steel Construction, Sydney, 1994, 2nd Edition
Design Capacity Tables for Structural Steel Hollow Sections
Australian Institute of Steel Construction, Sydney, 1992, 1st Edition