I saw these at the local lumber yard and thought they looked like a good thumbnail reference for an aspiring DIY'er like myself. I have a lot of experience with patch-or-replace jobs, but I'm rapidly moving toward more complex remodelling projects that will require extensive changes or completely new work.

Has anyone found these to be useful? Or are they more likely to get me in deeper trouble than not? I searched the forums here, but didn't find any past reviews or commentary (feel free to shoot me over the URL if I just missed it).

For reference, I live in Northern California.