As others have stated, the TS-Es are the way to go with this gig. I would think the 17 and 24 II would be the best options for you, but you would be the best person to determine the focal lengths needed for the job.
If you think you would do more architecture work, I think they would be prudent investments for you. If you buy clean used copies, you will probably not lose much money if you choose to sell them. The TS-Es are unique and that is their cache -- they can do stuff your other lenses cannot.
Re: online tutorials, here is a link for one on the Luminous Landscape:
http://www.luminous-landscape.com/tutorials/focusing-ts.shtml. I have seen others on YouTube and other sites.
The short explanation: Make sure your tripod is perfectly level. With the lens in center position, meter your camera. Next, using LiveView, focus for a far distance at 10x. Look in the foreground and adjust the tilt, if needed, to get the foreground focus correct. Then look to the distance again and adjust accordingly, followed by a review of the foreground again. This back and forth can be a pain, but it ensures that everything is sharp. The TS-Es are sharp from f/3.5 to f/8, which precludes diffraction. If done right, it will be sharp edge-to-edge. You do not need to crank down the aperture to get everything sharp.
A few tips: The 24 takes 82mm filters. The 17 is bulbous, so you cannot put a filter on it. However, there is a hack posted on the Fred Miranda forum about how to rig the Lee ND system to the 17 so that you can use ND grads. Google it if interested. The constant LiveView work requires patience and batteries -- make sure you have spares of both.

Check out my Flickr page. I have a Tilt Shift set. I also explain pros-cons of the 17 and 24.