well there are a few ways to make a sled.. you could go my rout an make it up as you go (lets just say my mom wont be skiing any time soon and i spent more time in the wood place at home depot, oh and i have a LOVELY scar on my thumb thats about 3/4 in long from a minor slip with a saw... at midnight... both parents asleep...) long story short the sled never saw the outside... not only because it wouldnt fit up the basement stairs but it want safe enough for dogs... i mean it was sturdy and heavy as heck and actually looked like a dog sled.. well for the most part besides the skies and lumber but i was more comfortable using something made by professionals so i bought one. Or you can use a website
http://www.ooowoo.com/JUNIOR/doityourself/k12sled.html http://www.geocities.com/Athens/Atlantis/1704/dog1.htmor what i would recommended the most would be to find a sled somewhere... it would ultimately be the best for new dogs and for a new musher... if one part of the sled is slightly off that could cause problems.. but once you have one then you could consider using it as a model to build your own along with websites.
Whatever you choose good luck!
PS. i got mine from sawtooth sleds in Minnesota.. its a toboggan.. the Sprint
http://www.sawtoothsleds.com/catalog.cfm?CatID=tobb its the first one... not pictured (don't know what happened to it) but it looks exactly like the one below... well more like the one with the sled bag i guess cause mine has one.. though its loose not tight like that
I also have been considering getting (maybe making) a good racing sled though mine weighs next to nothing (24 lbs)