You can adjust your FSB some in bios, 10% higher is very safe. I doubt you will have to adjust your vcore for 10% boost.
You will not be able to hurt your P4 overclocking, do not be afraid of raising the vcore when your ready to clock higher.
Watch your temps. keeping under 40c will improve stability.
Take small steps untill you know what your doing in bios.
You are limited to what your mind can perceive.