Cheat Sheets . . .

These may be a little dated, but at least they'll get you started on the possibilities.

• Sage Quick Reference by W. Stein (03.09)
• Sage Linear Algebra Quick Reference by R. A. Beezer (12.11)
• Sage Elementary Number Theory Quick Reference by W. Stein (04.09)
• Sage Calculus Quick Reference by W. Stein (04 2009)
• Basic Math by P. Jipsen, version 1.1 (01.08)
• Graph Theory by S. R. Turner, version 4.7 (07.11)
• Abstract Algebra by B. Balof, T. W. Judson, D. Perkinson, R. Potluri, version 1.0 (06.12)