A Prime Case of Chaos Article from Volume 4 of What's Happening in the Mathematical Sciences by Barry Cipra, describing conjectural links between the Riemann zeta function and chaotic quantum-mechanical systems.
Not Always Buried Deep Notes on Analytic and Combinatorial Number Theory, originally written for the 2003 Ross Summer Mathematics Program, by Paul Pollack.
Riemann's Paper "Ueber die Anzahl der Primzahlen unter einer gegebenen Grösse" and in translation.