There's two parts to doing a stock from a blank:
1. Inletting the action and bottom metal into the stock blank.
2. Shaping the outside of the stock.
#2 is the easier part. NB I said "easier." I did not say "easy."
Part #1 comes in varying degrees of difficulty. First, there's two issues in inletting. The one issue that everyone sees is where the wood meets the metal of the action and the barrel.
The second part of inletting that most people never see is the contact between the bottom of the action and the wood. On high-end guns, having a wood/metal inletting on the bottom of the action is more "pure," but if you're not a purist, you could get the top line of the inletting tight, then make a clean, but non-contacting job of inletting below the top line and glass bed the action with Acraglas or something similar.
Now, if you want to go for the purist route, there are actions that are more difficult than others:
The early bolt actions like the Mauser and Springfield '03 are more difficult in a "purist" inletting job because they have smaller recoil lug surfaces and they have "lungs" in the rear of the action where wood humps up off the bottom of the receiver channel to catch the rear of the action.
The Winchester M70 has a cleaner bottom line and is easier to inlet along the sides. A pre-64 M70 is a little trickier for the rear tang.
A Remington M700 is pud-easy, because it had a pretty featureless bottom and the recoil lug is removable so you could inlet that apart from the rest of the action.
I have no idea what inletting a Mosin is like. Personally, given the effort to inlet a stock & barrel into a nice piece of wood, I wouldn't ever bother putting a Mosin into a custom stock. It would be like putting leather seats, a fine English walnut dashboard and a racing motor into a Trabant. Sure, you've shown everyone that you're an excellent craftsman... but in the end, you still have a Trabant.
On all of the above, you'll want all your metalwork done before you start inletting. If you're going to put a new barrel on the receiver, or you want to use custom bottom metal, or you want to polish up the bottom metal or action, you need to have all of that done before you start inletting.
You'll need some inletting black:
The gold is typically used where the wood is too dark to see the black - places like dark woods used for foreend tips. You coat the bottom of the receiver with a thin coat of the inletting black and you put the receiver and barrel into the wood. You cut away the mark as you sink it in. You should cut a channel through the wood from foreend to the rear of the receiver with a ball nose end mill that is small enough to miss all the features on the bottom of the receiver, then inlet a) down then b) outward. Don't inlet outward first, you want to get the receiver and barrel down to the centerline of the bore.
Maple can have some really nice figure to it, but as others have said, it's hard. It tends to chip out unless your tools are very, very sharp. You need to consider the grain flow under your cutting tools very carefully. And when you're laying out the stock pattern on the blank, try to get good, smooth grain flow through the grip area up around the magazine on the rifle, and make the grain flow "rise" as it goes forward to the foreend. Don't position the stock so there's lots of figure in the grip area, or you might have to reinforce the grip by putting a steel rod down through it.
If you're really interested in going this route, there's a book which details the steps a professional stockmaker does a stock from a blank:
I have this book and it is a good starting point. I'll warn you tho, it is a long way from looking at the pictures to getting a usable stock under your rifle.
Tools: You'll need a set of chisels and gouges for your inletting. You'll need to make or buy a narrow (like 1/8") "dogleg chisel" to inlet the recoil lug on most any bolt action.
On the outside - a good, steady bandsaw is a nice way to hog off pieces you know you won't need once you get the outline drawn on the blank. Lacking that, I'd suggest a good coping saw. A planer to get the sides parallel and the top line perpendicular to the sides is a really nice thing to have. When you start cutting in a stock from a blank, having a flat top on the blank that you know is 90 degrees to the sides is a huge time saver when you start laying out the action and barrel on the blank.
You'll need to make or buy a set of inletting screws to keep the receiver upright as you're sinking the barreled action into the wood. These screws are usually made from simple cold rolled steel rod, with threads turned on the receiver end with a lathe. When you drill the holes for the receiver screws, don't go too far oversize, because this is how errors start to creep into the inletting.
Once you have the barrel and receiver inlet, you'll need to start inletting the bottom metal, trigger bow, etc. You want to mark the bottom of the receiver and lay out where the magazine has to come up from the bottom. Don't drill straight through from top to bottom, especially on maple. You'll want to drill halfway down from the top, halfway up from the bottom, so any break-out will be contained in the middle of the magazine height where you won't break out the receiver inlet channel, nor the bottom of the stock.
When you're inletting the bottom metal, don't pound the snot out of the bottom metal to get a reading with the inletting black. As you sink the magazine into the wood, if you drive the magazine or bottom metal in too hard, you could split the stock.
On one-piece bottom metals, you will want the top of the magazine to NOT make contact with the bottom of the receiver. If it does, then what will happen is that there is no way to tighten the action and bottom metal together against the wood - ie, the action and/or bottom metal will rattle around in the stock. To prevent this, keep the top of the magazine from touching the bottom of the receiver by, oh, 1/32nd to 1/16th of an inch.
Shaping the outside:
Oh, let's see - you should get a Nicholson #49 and #50 cabinetmaker rasps. I've been told by some that their quality has dropped since Nicholson has outsourced production to Brazil, I think. But if you get a chance in a woodworking shop or dealer to see them, you'll get an idea of what you're looking for and you can find equivalents.
You should look around for a farrier's rasp. When you need to make wood come off a stock quickly, a farrier's rasp does the trick.
Then you'll need a bunch of smaller files and such to work on details.
That's about all I can get off the top of my head just now...