Multiple Distinct Clocks Error

Good referrences, and this gives me the forum to push my favorite book for people settling on a coding approach, HDL Chip Design by Doug Smith. He has, for example, all the typical flavors of a Flip Flop written with example code "The way it should be done" for both verilog and VHDL. There are little dialog boxes pointing to and explaining how each variation in the HDL text gives you a slightly different feature. It's not deep, but if you are looking for the right approach to basic synthesizable code, this is the ticket.