My most recent wood shed I built to hold about 6 cords, and cost me about $600 using almost all new materials from Home Despot (shopping in NH for that 5% savings...) I built figuring on 24" lengths, but shorter or longer peices could be planned for instead.
My shed is nominally 16' long, maybe 15'6" actual inside space, and holds four rows of splits, stacked to about 6' on the low side and 7' on the high side. I roofed it with that clear corrugated "PAL" roofing - think plastic roofing tin, which was a large part of the cost, but was also the cheapest roofing I could find if looking for more than tarps.
I started with a stretch of reasonably flat and level ground that I cleared as much of the vegetation off of as I could. I wasn't fanatical about it, this is a shed folks, not a house...
I put down two 16' pressure treated 2x4's per row of splits, spaced 18" apart. I put 6" between pairs, so that each row would have 24" of width. (with 3" overhang on each outside). I cut another 16' PT 2x4 into two 7'6" lengths, and screwed one across each end of the long rows. The 2x4's were all set on the narrow edge. This frame defines the floor of the shed, and keeps the splits off the ground. Since the floor is left as dirt otherwise, permits aren't needed (why pay the gov't for nothing...)
These dimensions are what would be adjusted as needed for shorter or longer splits. I would adjust the number of rows to give an effective width between 6 and 8 feet, although it would possibly be easier to roof if the width was kept closer to 7 feet.
At each corner, I put an upright cut from another pair of 16' PT 2x4's. I could possibly have used non PT for this, but felt that since the bottom end of each upright is in ground contact, and they would be exposed to the weather that the PT would be better. The uprights were cut to give a pitch to the roof and allow as high a stack under it as safely practical. I decided to go with 6' at the back and 7' at the front. I could have gone a bit higher in retrospect, but that wouldn't have gained me that much. A steeper pitch might have been nice, but the longer that diagonal is, the more of a pain getting the roofing is.
I tied the tops of the uprights together with regular 16' 2x4's, cut on the short sides to fit the slope. To encourage everything to stay square, I put a couple of short diagonal braces made from the extra offcut lengths between the uprights and the outside floor members.
On each end, I put a section of pre-fab 8' wide by 6' high stockade fence, inside the uprights, with the fence cross members on the outside. These formed the endwalls for the stacks, and were both cheaper and stronger than plywood would have been. Since the tops of these walls are going to be pushed outwards by the stacks, the top lengthwise 2X4's are obviously going to be stressed members, which will help to support the roof. (Now that I have the shed filled, the fence sections are visibly bulged out...)
When I had first started to think about building a woodshed I happenned to find a bunch of PT 1x decking that was really ratty, but that I thought might be good for roof supports, so I snagged it. I now spread it out across the roof 2x4's diagonally to make the most of it, and spacing it fairly widely. I didn't have quite enough, so I had to purchase a couple of additional PT 1x6's to make up the extra that I needed. I used my trimming peices to jam under the frame to help even out some of the low spots in the ground. (had to do something with them...)
I then decided that the two 16' long 2x4's weren't really enough to hold up the roof the way I'd like, and were a bit too springy, so I got a 3rd 16 footer to put in the middle, and cut 3 8' regular 2x4's to add support posts in the center. I put the support posts in so as to bow the roof beams up in the center an inch or two.
I decided that I really didn't like the idea of using a tarp for roofing, and after looking at a number of options found the plastic PAL roofing was the least expensive option. The only problem was it comes in 8' lengths that were too short (remember that diagonal roof pitch?) or 12' lengths that were much more than I needed (Maybe I'll make the next shed wider?) I ended up getting a couple of extra 8' lengths and cutting them into 2' peices. Fitting them together with the 8' lengths, using the reccomended 6" overlap gave me about a 9'6" wide roof, enough to cover the width of the pile with about 6" overhang on each side.
The shed was open on the sides most of the summer as I was filling it, but now I have gotten some heavy duty silver poly tarps from Harbor Freight and hung them (nailed them with my 1/4" crown air stapler...) from the 16' roof beams. This gives good protection from wind blown precipitation, but the space under the roof still lets the stacks breath. I might also get some level of greenhouse effect from the PAL roofing. When I need to access the wood, I can simply roll the tarp up and hold it up with some recycled "lettuce velcro" (very useful stuff BTW)
So far I haven't found a need to tie the bottoms down, but if I do what I'll probably do is just try tie-wrapping the bottom edge to a peice of pipe to give it some weight.
Hope this is useful - I haven't seen much else in the way of how to build wood sheds for less...
Goosrider