All you need to know.. (not quite, but will do for now..)
-Wall is must (enable all warnings all)
-g (if you want to debug at all)
-gp (for profiling support)
Debuggers: ddd a really nice frontend for gdb (once you get used to it).
Profiling is really neat. You can find about everything you need to know about it here. Kprof is an altertive analizer and bit more userfriendly.
Also I highly recommend that you use autoconf/automake to generate Makefiles.