Hacker News Reader

Hacker's Delight by Henry Warren.

Don't get distracted by the name, it's about binary mathematics. Bit twiddling at its finest.

I second this choice. Be sure to get the second edition and to read the various fascicles for Knuth's Volume 4 of Art of Computer Programming. Volume 2 has some useful content as well.

Reply on news.ycombinator.com