Do it the way it was done before chainsaws.Well yeah. But I either have to cut them into firewood, or I can cut them into boards. Either way, I have to do something with them. None of the lumberyards here will buy them or even take them unless they are the ones to fell them.
Cut them into long lengths. Split them long. Only when they are size you want - then cut to the lengths needed.
This keep your options open.
8 and 12' lengths would be good for building, and nothing shorter than 4' unless you're sure its just fire wood.
If you don't want or terrain doesn't permit you drag the logs, a blue ox is handy.