since this is your first box im going to assume you are going to go sealed, not ported
for a sealed box it should be about 1.4ft^3 for 2 10" assasin subs according to ascandesant audio
find the dimensions you want to use (h-w-d)
and then multiply them together then divide by 1728 to find out how many ft^3 the box will be
11.5x24x10=2640/1728=1.5277 ft^3 which would give enough room for driver displacement and is large enough to mount bolth subs
dont forget that this is the INSIDE dimensions of the box
before cutting pannels dont forget to include the thickness of the wood into your mesurements
make shure you have you have lots of clamps, a circular saw, a straight edge, wood glue, screws, a power drill, countersink bit, and a router or jigsaw to cut holes for your subs
but for actually building the box, simply cut pannels to size
put wood glue at the seams, make shure they are 90 degree angles or at least close, clamp them and seal them with counter sunk screws, dont forget the countersink or else your wood will split
once the box is assembled you can cut holes with a router and a jig, a jig is easy to make just search the forums
once your box is all together and your sub holes are cut, most people seal the corners again with a silicone based caulk, but make shure to let it dry before you put your subs in, i have heard that the fumes from the caulk drying can destroy the surround on the sub
as for runing wires, you can install a terminal cup, or alot of people simply drill a hole in the box and run the wire straight trough it then seal it with caulk
anymore questions just ask
it is a good idea to check out the stickys in each forum, they contain alot of useful information
what part of wisconsin are you from?
feel free to pm me if you have any other questions