“A flexible system of fonts designed specifically for code… It offers both monospaced and proportional fonts, all with a large range of widths, weights, and styles for richer code formatting.”
A Comprehensive Guide to Font Loading Strategies
Typ.io: Fonts that go together
6 Great Contemporary Alternatives to Helvetica
Typecast by Monotype
Design with web fonts in the browser. Use Typecast to create visual and semantic designs. Check for readability, rendering and beauty then share a working prototype of your design.