If you want a review of basic probability theory and statistical inference, I suggest the following:

- Chapter 1, A review of basic probability theory, in Tuckwell, Elementary applications of probability theory. The most important material for us is in sections 1.1-1.4.
- Chapter 2, Using Likelihood for Estimation, in Borchers, Buckland and Zuccini, Estimating Animal Abundance
- Casella and Burger, Statistical Inference, esp. Chapter 1 on Probability Theory
- Hoel, Port and Stone, Introduction to Probability Theory. More introductory level than Casella and Burger.