Fireplaces are great at heating up the house. I modded ours up a little, put some heatsinks on the top and a low RPM fan on the other side. We also put in some ducting near the top of the chimney, sucks heated air from the top and vents it to other parts of the house. Works nicely IMO
For wood, we just grab any old bits of timber we see. Someone pulling down their patio, redoing their decking, redoing their roofing, etc. If they dump it out the front verge or in a skip, we just drive past, load it in the car/trailer and bring it home. Chop it up with a drop saw, stack it on the side of the house. Do that all year round just whenever you happen to see good wood, and when winter comes you just grab the pre-chopped stuff from the side. Free and semi-easy!