IMO, the biggest improvement in accuracy for the 10/22 is to replace the stock barrel with one of the aftermarket or even the factory bull barrel. These can range anywhere from $75-$400. Again IMO, you don't really need the higher end barrels to get down to 1 MOA. To fit the barrel, you'll need a new stock or mill out the factory one. Another $60-$500 depending on how nice it looks or add-ons like adjustable butt, accessory rail, etc. A number of manufacturers like Butler Creek sell barrel/stock sets for sale to simplifying the purchase.
The next thing is the trigger. There are plenty out there and you can actually improve it yourself to a point by a little grinding.
Everything else is gravy that will make the 10/22 only slightly more accurate. You can thread the barrel to the receiver, bed the barrel/float the receiver, bed the receiver/float the barrel, two stage trigger, square the bolt to the barrel, bolt the scoperail/base to the barrel, bolt the scoperail/base to the receiver and the barrel, you name it. These will, of course, cost more money, usually a lot more money.