Serial Port
Complete Second Edition The second edition of the ever popular
Serial Port Complete.
Serial Port Complete
Develop
projects quickly with schematics and code for these applications:
PC-to-PC link, PC-to-embedded-controller link, RS-485 network, simple
Stamp network Original applications and other useful tools and
routines on disk. and much more!
Parallel Port Complete
The complete guide to using and
programming the PC's parallel port.
3rd edition USB Complete by Jan Axelson.
USB Complete
is a developer's guide to designing and programming USB peripherals
and writing the applications that communicate with them. The new
3rd Edition is updated from start to finish, with new and expanded
information in all areas.

Easy
CNC by David Benson; A Beginner's Guide to
CNC. This is an excellent book for robotics builders, or anyone just
getting started with CNC.