I would teach lowercase first. The majority of printed text anywhere is in lowercase. From the research I've done teaching uppercase first can slow down the process of learning to read by confusing the child. I used a moveable alphabet I printed from montessoriprintshop.com. I also found a couple sets of lowercase magnet tiles. One set was the fridge type, but they were a nice, soft foam. Amazon,com would probaly have something like that.
it really does! i've been doing it with my 4 yo (he's going to start kindergarten next school year) so i figured i had the extra time to spare. at this point, he recognizes all the letters, both upper & lower case. he's not that great at writing yet, but i figure i'm on the right track.
I thought about doing it this way using a letter of the week curriculum but those take a while.