He has told me that since they just spent $200 on a fire pit, I can either use the axe we already have, see if I can borrow my grandpa's 8# maul, or use my own money for tools
Ccnati,
Check out this thread: http://www.bladeforums.com/forums/showthread.php/1328154-Need-help!-First-hang . It was started by someone else and then I somewhat hijacked it hoping others would search & find it rather than asking "first axe/hang" questions over & over. It helped me a bunch so it'll probably be a good read for you as well.
My experience with NW woods differs strongly from yours. I find that most of the wood I get can be split with a 5 pound axe very handily. There are a few pieces that won't split with the axe but will with the maul. But for the most part I go from axe to sledge & wedges.
For very hard woods like London Plane or Elm wedges are the only thing that works (until you get them down to size) and it's best if they are very sharp and have a slightly concave bevel grind. The concave grind makes the wedge stick in the wood instead of trying to pop back out. For the same reason (sticking) you never want to put a concave bevel on an axe unless you want it to stick badly - i.e. you're using it for underbucking with a crosscut saw.
I guess it probably depends on exactly where you live. Having been to each of the 48 states (not AK or HI yet) I can say we have a very diverse country and even within the same square mile, vegetation can change dramatically based on changes in soil or elevation. Here in mid/southern New England we have a lot of maple, pine and oak, with the occasional birch, ash or other. Even within the maples their hardness varies greatly between a Sugar Maple and a Red Maple. The base/trunk of the Sugar Maple I just cut down is just shy of 30" in diameter; that little Plumb Boy Scout hatchet (my "first hang") split sections of that tree you'd have thought a 5lb axe was required. Then again (because of the knots), there were sections that a hatchet should have been able to split easily yet that 5lb Collins axe bounced off of them and a maul + sledge & metal wedges were required.
That tree was a little bit of a different case because I cut it down and then split it straight away. Splitting dry wood is usually always easier than wet/green wood. For the most part, anything under 12" in diameter, with no knots, that 5lb Collins axe split easily. Anything over 12" in diameter, the maul splits easily and very rarely do/did I need the sledge/wedges.