Been down this road several times, twice on my own boats and three for hire.
Do not use green treat as AC2 is corrosive with aluminum when it gets wet. My understanding is, the only difference between marine grade plywood and regular plywood is that there are no air pockets between the laminations with marine grade. I've seen both used. I would spend the extra for the marine grade because when you are done you will swear to never do this again.
Like Guy said...a multitool will save you a lot of swearing. Console will only need to be freed from the floor, you don't necessarily need to take it out as you can slide the new flooring underneath it. if you have a strorage space under your console, many times, the new floor under the console can be screwed from the bottom of the support with a shorter screw... screw sucking it down.
Typically your livewell will sit on the boat frame and your floor will be on top of the flair/flange at the top edge of the live well. It is a good idea to put some sealant between the live well flange and your new floor. This way when water is splashing around in the well, it wont find its way between the live well and your floor ending up down in the hull.
Generally the floor will be in sections, depending on the degree of rot, try to get the pieces out whole and simply use them as pattern for you new floor. If you are putting down new carpet, pay for the factory quality stuff rather than the midgrade/Cabela's stuff, you will be happy you did in 2 years. Also if doing carpet, when you get to the little pieces (bow, fuel tank cowling, etc), carpet them before you install them.
Stainless steel screws and bolts are a must. Make sure you pre-drill you holes through the metal floor supports as the stainless steel screw heads will strip out much easier than a regular screw. An impact driver and proper size bit for the screws is a good idea. I've had good luck with the SS screws from fastenal. They may have to order them from another store so it could take a day to get them.
This is also a great time to inspect every wire in your boat since it is all open. Buy some shrink wrap and seal every conection you can find. If you find wire lying on the hull, secure them up so they are out of any water than may run through the hull. It will only take you a couple hours and save you frustration down the road with grounding/vibration issues. Also a good time to consider new battery trays/boxes, hatch pulls, live well plumbing, etc. You can take this stuff as far as you want.
Last but not least...take your time & spend extra for quality when you can. When you find youself getting pissed at a stubborn screw it's time to take a break. Don't expect this to be a weekend project.