I'm in the same boat, eventually I'm going to clear out all the junk I haven't even thought of in years and convert it into a bonafide workshop. As for suggested items:
- Lots of light (I use high-efficiency florescent bulbs)
- Heat source (you'll of course be spending LOTS of time in there and Ontario sounds cold, might as well make it comfortable)
- Mini-fridge (like I said, you'll be spending a lot of time in your workshop)
- A storable work table, I figure a 6' x 3' folding card table or something similar would do the trick. Good for laying out your TK or other in-progress costumes
- Clothes rack for TK undergarments and soft costumes (you can build one out of PVC pipe sections)
- Organized tools & supplies storage area (nothing more frustrating than not being able to find the right tool or part, especially when you KNOW you have it around somewhere)
- A wall or bulletin board to hang reference photos
- A computer, or at least somewhere safe to plug in your laptop
- Music player
Definitely take progress photos, I'll be looking for some inspiration.