I have incorporated some results I like in algebraic graph theory into my notes http://math.mit.edu/~rstan/algcomb.pdf. See for instance Example 9.12 (number of spanning trees of the $n$-cube), Corollary 10.11 (enumeration of binary de Bruijn sequences), Section 11.5 (squaring the square), Section 12.3 (complete bipartite partitions of $K_n$), and Section 12.5 (odd neighborhood covers). Many other nice examples are in Matoušek's Thirty-three Miniatures.