If you are stuck on a specific derivation, many find it helpful to cross-reference . While the style is different, the mathematical approach to the Bose-Einstein and Fermi-Dirac statistics often provides the missing link needed to solve McQuarrie's problems.
Topics: Probability, ensembles, the Boltzmann factor. Challenge: These are "equation-heavy." You might be asked to show that entropy ($S = k \ln W$) is extensive. Manual help: The manual shows the algebraic chain linking microstates to Stirling’s approximation. Mcquarrie Statistical Mechanics Solutions Manual