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Among others you should also have gprof and valgrind ( or something in it's class ).
Seconding swilliams, I'd say the basics are:
Other than that, I'd say install as you go. Linux is more about little utilities that each do one thing than monolithic development environments that do everything. So if you find yourself needing something, you can always just install it, be that thing a memory profiler, a documentation generator, a bigger/smaller/more different editor, et cetera, et cetera.
Another great utility that you can use are *nix man pages. Each function in the C library has an associated man page.
For example:
man printf
man strncpy
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