For the hardwood floor, you need a pneumatic floor stapler, a mallet and an air compressor. Suggest you rent the stapler (mallet should come with it), as it is about $400 to buy. I just laid 400 sq ft of oak and can attest to the pneumatic stapler as mandatory. A box of 5000 staples will run you $40. Don't be chintsy with the staples, and be sure to staple near the ends of the boards to avoid squeaks. But not so close that you split the tongue.
You will need a flat subfloor. I laid 1/4" luan over mine as the CDX was pretty rough. Then you put a black plastic vapor barrier down. I used a pneumatic stapler for this (not the same as a pneumatic FLOOR stapler), as the plastic slides around and the stapler lets you reallly fasten it down quickly and easily.
It took me 2.5 days to lay the hardwood floor (all the prep time - luan, etc.. was extra time) - had a lot of trim work. Oh yeah, a power miter saw helps a lot to get good, square clean cuts on the ends of your boards, if they are going to show, as in a doorway/entry to carpet or some other floor.
good luck. It's a lot of work, but very satisfying when the job is done.
Bob