FPGA Central

Hi,
are there any free books on HDLs (verilog preferred) online?
I found several "getting started" tutorials, but what I am looking for is
- the workflow to get some kind of a "hello world" program running on
the example of any development kit.
- some examples with simple hardware interaction ( eg. RS232
communication, logic analyzer, ...)
- maybe the implementation of a very simple processor
- special features like PLL or DCM usage
- a brief reference of the HDL
- all contained in one pdf, if possible.

If there is no such book online, which one do you recommend to purchase
to get practical experience using verilog for a Spartan 3 based
development kit?

Jens