Having heated a house for 6 yrs primarlily using wood not all wood is equal in using it for heating. Some tree species burn much better than others.
Plus, wood needs to be properly dried to burn the most efficiently. One can short-cut that by cutting dead trees that have stood dead for awhile to naturally dry out.
Pitchy tree species are pretty bad for use, and hard wood species should be cut/split when green before set aside for drying. I dried all my wood for at least a year before use so one needs to plan ahead not just on the upcoming heating season but the next.
It's alot of work to cut your own, along with equpment & transportation costs. That's worth it if you have easy access to ample supplies like on National Forest lands, but one has to factor in those costs with what it would cost to buy from another person that does the hard work.
Maintaining your stoves is esential to reduce ceasote build-up, and clean the chimney.
Lastly, cutting your own wood is dangerous running a chain saw and dropping trees.