I don't cook with tofu too much, but when I do, this is what I do. I buy extra-firm tofu. When I'm ready to use it, I take it out of the package and drain it, and then I place it on several paper towels on a plate. Then I put several paper towels on top, and put something heavy (like a cast-iron pan) on top - this presses the tofu. A lot of liquid is released, which is why there are paper towels! After maybe 30 minutes, I replace the paper towels, flip the tofu over, put the heavy item back on top, and press it for another 30 minutes. It just makes it more dense, and I think yummier. It doesn't have to be for an hour, you could do more or less time - that's just what I usually do.
Anyways, once it's pressed, I cut it into pieces (usually cut the loaf into 8 slices, then cut each slice into 2, I think, or maybe 4?). I heat up some oil in a pan, and I fry each side (top and bottom) until they are golden. Then I add some veggies and quickly stir fry them, and serve over rice with whatever sauce (I like a thai peanut sauce, but teriyaki would be good too).
Another way I've cooked it before is similar - but instead of pressing it, I freeze it ahead of time, and then the morning I'm going to use it, I take it out of the freezer and let it thaw. It has a totally different texture then - it's more airy and chewy. But I cut it the same way, and then fry in oil.
That's about all I've done with tofu. Oh, I've also breaded it, kind of. So I pressed it, as described above. Then I cut it into 8 slices. I dipped in a bowl of flour, then water, and then coated with a breading (I don't have the recipe in front of me - I think it was ground up roasted acorn squash or pumpkin seeds with spices and cornstarch), and then fried it in 1/2 inch of oil. That was quite yummy - it's part of our Christmas dinner, along with stuffed acrorn squash and brussel sprouts. So I only make it once a year