modeling users - up to 6.2.2 (p.295)
modeling users - up to 6.2.5 (p.306)
modeling users-up to 6.3 (p.312)
up to 6.3.3. on p. 320; remember comment added at p. 319
make a basic user model (including secure password) - up to p.328, through section 6.4