It's actually been a very long ongoing project. From the removal and relocating of all the plants in that garden area, to actually breaking ground and getting some sawdust flying...it's been 2 months. It was difficult to find places for all the rose bushes that came out of there. atleast 6 went in the ground and 5 more in pots. Other C&S plants are still awaiting homes. Soooo inbetween other life stuff, i've finally gotten to the point of calling it a shadehouse!
I'm posting all this here, hopefully, for the benefit of anybody thinking of building something similar. It may not be as easy as it may seem. Alot of physical labor is involved, as well as proper preparation for a long lasting structure. I'm also posting so you have a bunch of pics to look at to kill time if your bored
9-28-2009
Removal of garden plants
Mainly just a whole bunch of rose bushes and a few C&S along the front border to be removed. The lanky and awkward wisteria and arbor was no easy task to move. The roots had gone through the drain holes making it a bear to get out. The drag across the yard wasn't any fun either...
This is it, in its new home on the opposite side of the yard. 
Removal of grass!!!
Well, Jen had left me on my own for too long and i acted on one of those *stupid ideas* i get
Installing the posts for the frame
Ok, so now were getting somewhere. This is the most important part of the project. Take the time to measure alot and double check everything. If the first post is not plum, the rest of the structure will also be outta whack. The 4x4 posts are set into metal brackets with 2 foot long blades that you pound into the ground. I thought this would be easier and/or better. Meh, it's marginal. The only advantage is if a post were to rot, break, crack, whatever, a new post could easily be put in its place by undoing 2 bolts.
Leveling the ground, weedblocker fabric and gravel floor
Using the garden soil leftover from the greenhouse build last year, we filled in where the grass was. The area is not perfectly level, as by doing so would bring the soil level low enough down the wall to start to expose the footing. So it slopes by 3-5 inches. No biggie. I then applied an Ortho product (sorry forgot the name) but it's a ground clear chemical than kills/prevents growth for up to a year (so it claims) I didn't want to deal with any weeds or grass growing, so hopefully this along with the fabric will do the trick. 2 tractor scoops of 3/4 inch gravel was used for a 3 inch deep floor with a little bit left over.
Framing brackets
I used various metal brackets and stiffeners for the upper parts of the framing. It was easier to work with and came in real handy when working alone.
Benches/shelving/staging
Whatever you want to call them...they are the parts where the plants will go on
I went with a 32 inch bench height. Kinda low for me, but not too high for Jenni. Allows me to lean over to the back and allows Jenni to see the back
3 of the 4 sides are 36 iches deep, the door side is 30 inches deep. Allows for 30 inches of walkway. Enough to maneuver comfortably without fear of knocking plants over.I also framed out a doorway. Why on the long side and not the short you ask? 2 reasons. 1) On the short side, i'd eventually constantly be attacked by rose bushes. 2) calculating the square footage, i get 1.5sq.ft. extra
As small as that is, the more space the better!
Bench top slats
After using regular tables and plywood tops for benches in the greenhouse, i knew i had to use a different method. I've seen this slat method used in nurseries all over, so i went with it. My only concern is i have alot of small pots and they may tip if moved or whatever since the slats are only 1 5/8 inches wide. But i love the way it turned out and i think the small pots will be fine.
It's a long and tedious process. The slats need to be pre-drilled and cut to size. I then use the cut ends to act as spacers for each slat to ensure uniform spacing throughout. This method works great, just takes awhile. I managed this one 8x3 foot bench in about 2hrs tonight.
I used 2x6 lumber for the backings, as i wanted a lip to kinda act as a backstop for the pots.
Well, thats as far as i've gotten, as of tonight...more bench slats tomorrow, maybe another small upper shelf along the short back wall, build the door and then the final step, the shadecloth!
Luckily it was a tray of columnars i had staked with skewers, no damage done 
I will say that in the end it was worth sacrificing some of my lawn because now my cactus are in there too!!! (I have about a 6' section of claimed plants)