Hi,
Search here in edabord there are a lot of books. Try to find the one that you need because this depend on applications.
DSP and Microprosessors
FPGA
Matlab
Image processing and so on.
In fact, you need to have enough point to download these books.
1. Applications Of Digital Signal Processing by Oppenheim
2.Multirate systems and filter banks by P.P Vaidyanathan
3. Advanced DSP by Glen Zelnicker & F.J Taylor