A huge collection of agricultural buildings provided by the University of Tennessee.  Check with current building codes in your area for compliance.

http://bioengr.ag.utk.edu/extension/extpubs/PlanList97.htm

I've been designing this shop/studio/garage for the last couple of months, its 24x48, I might increase the size to 28x48.  Anyhow, I'm pretty new to construction so I've spend some quality time reading up on framing, concrete etc...  I think I'm almost there with the design but I found this board that has answered some of my questions so I thought I might post up some screenshots so I can get some feedback before we start spending money...


More pictures here:
http://design.medeek.com/studio/

Currently working on a new garage design with attic and dormers.  This one will be a 3 car garage with a stemwall foundation, 12/12 roof with attic and dormers.  Similar to the previous shop design I will be adding and alternate upstairs floorplan that has an apartment/living quarters for a single or dual occupancy.  Unfortunately, I have been very busy with other engineering work and am just now getting back to the site. 

I've attached a couple screenshots below of the work in progress.  Note, that this time around I am going with a drop top chord on the gable truss so that I can use 2x6 outlookers.  For high wind areas I think this is the better way to go.  It also eliminates the thorny issue of cutting into pre-manufactured trusses.