Go stones, boards and books are available at Ishi Press, Samarkand, and Yutopian (and Kiseido) via mail-order. They are also available in some game stores in Sacramento, such as The Game Keeper in the Downtown Plaza.
A cheap set may cost between $15 and $30 with a vinyl board and plastic stones, while a nicer board with glass stones may cost $60 to $150. (Take care to observe the size of the board when purchasing a set, as cheaper sets often use 9×9 or 13×13 boards to save money on stones, or use tiny plastic stones that are easily disturbed during play. These sets are ideal for learning, but this warning is intended to prevent surprises.) The board, stones and bowls (to hold the stones) are often sold separately.