The Source for this Mitzvah: Berachot 4b-5a
Number of Sections of the Shema to read: Tos. Berachot 2a #1, Rosh Berachot 1:6
Protection against Mazikin [Damaging Spirits]: Berachot 5a; Tos. Berachot 2a #1
For Torah Scholars: Berachot 5a
Associated Blessings: Tos. Berachot 2a #1; Rosh Berachot 1:1
Additional prayers: Rosh Berachot 1:6 Forgiving others nightly, before going to sleep, earns long life: Megillah 28a
The Bed of one who skips Recitation of Shema is likened to the bed of a Gentile woman [in terms of danger to him]: Berachot 8b, Pesachim 112b
