A sleep function? svcSleepThread(s64 ns); Where ns is in nanoseconds. You can also create events and mutexes which you can wait on with svcWaitSynchronization or svcWaitSynchronizationN. If that does not answer your question then try to be a little more specific.
It's in nanoseconds. If you need a delay which are actual seconds, multiply it by 1.000.000 (1000 * 1000, because multiplying by 1000 will give you milliseconds, and then another 1000 will give you actual seconds). If you only need a specific amount of milliseconds, just multiply it by 1000. So if you're trying to wait 5 seconds, 5 * 1.000.000 should do it.


int i;
for (i=0; i<= 60; i++)
gspWaitForVBlank();