jack frost, also youtube videos (friscoboater), also just research here on the restoration forum. If you are using a computer or ipad you can see how many discussions and views each topic has, just look for popular threads that have a lot of each and you will usually find a good restoration with tons of advise.
.1) The stringers seem fine and are completely enclosed in fiberglass and or expoxy.
Usually the stringers will be rotten before the floor. Generally rot starts from the stern, transom low on stringers and possibly at the same time on exposed part of the deck where something was attached via screws and wasn't sealed correctly. Chances are the wood inside your stringer is wet and starting to rot or already is.
.2) When cutting the floor out is okay if my blade gets into the stringer?
Yes, take a skil saw and set the blade depth at the same thickness as the deck. Start cutting a few spots away from the sides and fuel tank to see what is under the deck and confirm your blade is set to the correct depth. Then start cutting along the sides about 3 inches in from the sides. Look at how the hull is designed underneath before you start cutting. Cut small sections I would start where the wood is already rotten or soft and work your way from there. cutting into the tops of the stringers is no big deal because you are probably going to be removing them as well. cutting into the top of the fuel tank is a very big deal so know where that's is if you have one that is below the deck. If you do have to remove stringers some try and remove them in one piece to use as a template later. Also before you start removing anything or cutting anything take a 1000 pictures and measurements and then take some more you will need them later.
.3) Where is a good place to purchase marine grade plywood?
Most don't purchase marine grade plywood but if you have any decent lumber yards in your area they should carry it at about $90-$110 a sheet for 3/4". I used plywood from HD and that other big box hardware store. Do not use anything that is treated. I cant remember what it was call but it will be an exterior grade AC plywood, this will usually have less laminates then marine grade but uses waterproof glue. Just Google plywood grades and read up on that. If you have the money and just want to say I used marine grade plywood then as they say here "Its your boat and you get to do it how you want to", but its not necessary.
.4) Is the wood (do you mean the deck) screwed into the stringers?
Hard to say because every boat manufacturer makes their boats a little different then the next. I don't think mine was, the deck was glued to the stringers using a thickened resin we refer to as peanut butter (PB) because of its thickness and consistency being like peanut butter. When I put my new deck in I PB it to the stringers, bulkheads and sides and then I used stainless steal screws as well.
.5) What supplies will I need, what brand is best and where is a good place to purchase all of this.
Woodonglass put an excellent link on here read it lots of good info and once you have watched fricoboaters vids and researched a bunch of these restorations go back and read it again because it will make a lot more sense. Check on line for fiberglass distributors and compare prices and shipping costs which are a lot because of the materials they will ship are considered hazardous and rightfully so. Look for a local place. I have lived here in Panama City for over years and never knew I had a local ship builder that sells to the public for a very reasonable few plus no shipping costs. Even the ship or boat builders that don't normally sell to the public I found out if you ask they sometimes will make you a deal. Cant hurt to ask.
.6) I have pics of the boat and will get them uploaded.
Get a free Photobucket account and look for the link on iboats that will tell you how to use it.
.7) Thanks for any help or advice out there and if anyone has pics or video of this process I would greatly appreciate if you could share them.
Again friscoboater is a good place to start he has hours of good videos and also look for Goldie627 here on iboats I like his videos because when he started doing them he was a beginner to restorations so its easy to follow along and learn from what he does right and where he shows you he went wrong.
Look for these names and check them out also. Nurseman, Corjen1, Woodonglass, Bigdirty, ahmincha, sphelps, Red Herring, gm280, KnottyBuoyz, AllDodge, GWPSR, jbcurt00, WOEISMEIGOTTA470, luke000, Yatch Dr., saginawbayboater and about 50 other guys on here. All great sources of info. Hope this helps.