Before you do anything carefully examine the lay of the land where you want to build. You want to determine where the water flows, and collects, during rains. Use a hose if you have to. Some forethought now can save you a bunch of grief later.
Depending on the soil conditions, size, drainage etc. you might want to rent a compactor to get the ground psi up to 4k or so.
If you have any closet skeletons, use this opportunity to get them out of the house and bury them where they'll never be found.
The wire mesh, or rebar if you go that route, needs to be above the base material, so it's positioned in the middle of the slab, not underneath it. You can buy "dobbies," usually small concrete blocks, to do the trick by supporting the mesh 1" - 2" above the gravel bed.
Wipe a little diesel on the forms to help them release easier.
Now's a good time to hit the phone and call in any favors you may be due, you really want the help of someone who's done this before.
Might as well go all the way and put down an epoxy coating. For that put down a "light broom finish", which is exactly what it sounds like. It's also easier to achieve than a smooth as glass finish when you're doing the pour. Go for the light broom texture, and let the epoxy get you that final glass smooth floor.
