<p>When building projects in C++, I've found debugging linking errors to be tricky, especially when picking up other people's code.  What strategies do people use for debugging and fixing linking errors?</p>

One of the common linking errors I've run into is when a function is used differently from how it's defined.  If you see such an error you should make sure that every function you use is properly declared in some .h file.
You should also make sure that all the relevant source files are compiled into the same lib file.  An error I've run into is when I have two sets of files compiled into two separate libraries, and I cross-call between libraries.
Is there a failure you have in mind?