If I can't pay my taxes now, should I still file on time?

If I can't pay my taxes now, should I still file on time, by the October deadline? And does the system require me to make a partial payment at the time of filing (or at a nearby deadline)?

 

And if the system DOES require me to make a partial payment at the time of filing, how much is that payment typically? I would assume it would be a percentage of what's owed.