You can find advice online when planning to build a cabin, so if you can find any specialist websites you should be able to find helpful advice to help you do so.
You can obtain log cabin building plans from several places. Golden Eagle Log Homes has both stock and customized building plans. Log Home Builders can work with you to create the floorplan and building plan that you want as well as helping you with contracting qualified builders to erect the structure.
You can find timber deck plans on the web at their website www.timbertech.com. They offer a variety of plans online.
http://entertainment.howstuffworks.com/how-to-draw-buildings11.htm I used this to draw a cabin for school.
There are some contracting companies that would be willing to draw up some deck plans for you for a price. You could also get a book on building decks, or buy plans.
In the UK the government announced recently a programme of building new nuclear power stations. Interested suppliers are invited to submit plans for consideration. Building might start by 2011.
You should look here: http://www.deckplans.com, as it is the best place to go get building plans. There are people here you can talk with and exchange building plans
Plans Now has different plans for building garage work benches. These plans can be found at: http://www.plansnow.com/workbenchplans.html.
The best place to look for such plans would be online at www.mscsinfonia.com. A computer program could be used to replicate these cruise ship type deck plans that could be used for your backyard deck.
An architect or building designer.
Architects.
There are many great free deck building plans online. You can go to www.deckplans.com or www.decks.com to get these free plans.
Here is site with a number of free pole building plans. Not sure if the exact dimensions you are looking for are there, but I'm sure some of these could be modified to work.http://www.ag.ndsu.nodak.edu/abeng/plansGood luck.