[MaSnaka]

Concrete is always guaranteed to crack. The rebar and wire only keep the cracks from seperating. You definetly want a footing at the perimiter where your walls will be anchored, which will require anchor bolts (J-Bolts) imbedded 12" from the corners and 30" in the field. Atleast in California. I don't know the specs or building codes in your area but you might want to check them out before you start pouring. Also don't forget the moisture barrier, usually 6 mil poly sheeting with an inch of sand above and 2" below. This will keep moisture from wicking up through the floor from the ground below. You have had good advice from the others imo. I just wanted to add.

John