For the next 3 weeks' lectures (circuit size lowerbounds), the 
best sources are:
1) Ingo Wegener ``complexity of boolean functions,'' Wiley-Teubner series
   in CS, 1987

2) Bopanna and Sipser ``complexity of finite functions,'' 
   In ``Handbook of Theoretical computer Science, Vol. A'' edited
   by J. van Leeuwen, 1990

For the following 3 weeks' lectures (circuit depth and communication complexity
lowerbounds), the best sources are:

1) to some extent, 1) above.

2) Mauricio Karchmer, ``Communication complexity and Circuit Depth,'' MIT press
   1988
3) Kushilevitz and Nisan, ``Communication complexity'' 1996.