Remember that Verilog is a hardware description language, and an FPGA is digital hardware, so you will need a basic understanding of digital design.
If you already have that knowledge, then go for it! A good way to get started is to buy an inexpensive "starter" development kit from Xilinx or Al.tera. It should include a small FPGA board and software development tools. Play with it, try the included example projects, and then try writing your own little projects.
I learned Verilog mostly from the techniques and examples in the Xilinx XST User Guide. For detailed Verilog reference, I used the IEEE 1364 standard.
You will encounter a *huge* amount of documentation and software (many thousands of pages and several gigabytes), so prepare yourself for that.