If you are looking to learn how to use a disassembler and debugger to reverse an application, I recommend the CMU binary bomb lab. You can download a self study version of the executable
here. This is the same lab that a lot of computer science programs use to introduce using a disassembler and debugger.
This document is the write up for the assignment provided by CMU; if you ignore all of the scoring stuff, the rest will be very helpful. Note that you will need a Linux environment to run do this lab (I recommend using
Ubuntu, but any distro should work). The tools you will need are gdb, objdump, and strings. Objdump and strings are part of the
binutils package, and
gdb is its own package (called gdb). You will be able to install these packages with your distro's package manager (apt in the case of Ubuntu) fairly easily (the links I gave were simply for informational purposes). If you want to hone the skills most pertinent to console hacking, try to do this using only objdump and strings.