Before reading and studying the results on random graphs included in the text one should become familiar with the basic rules of asymptotic computation, find leading terms in combinatorial expressions, choose suitable bounds for the binomials, as well as get acquainted with probabilistic tools needed to study tail bounds, i.e., the probability that a random variable exceeds (or is smaller than) some real value. This chapter offers the reader a short description of these important technical tools used throughout the text.