There is a lot of great information on the pages of a mister "Toothless is my middle name", but this page about building a skateboard press is the one that has me excited. I am really not sure why I turn to this instead of the "Dimm" press. I am sure both can turn out some nice boards.
If you are going for mass production you can go all the way to a concrete mold method. Seems like you could get into a decent amount of trouble with that.
For my own baltic birch aspirations, I may just be going for another flat board, and whatever heavy objects I can find around the house.