Some lecture notes on critical percolation, starting from the beginning and ending with Kesten's scaling relations.
I. Introduction and Existence of Phase Transition
II. Basic Techniques
III. Rescaling and Scale Invariance
IV. Characteristic Length and $p_c = 1/2$
V. "Fences and Corridors"
VI. Universal Arm Exponents
VII. Variation of Parameter
VIII. Kesten's Scaling Relations