If you use large ones (which are usually steamed) I would bake them in a covered pot to retain moisture... otherwise they will be quite dry. Remove bottom leaves, the top of the artichoke (where the points are) and snip the points off the remaining outer leaves. Trim the stem. Cut them in half. Rub all cut ends with lemon.
I would be tempted to add a bit of veggie stock or chicken stock to the pot with olive oil, more lemon juice. Reduce what is left and season as a dressing.
I think you hack off a couple of a rows and sort of expose the "heart". At restaurants, i've seen it served with part of the top cut off, and some of the remaining leaves peeled back, like a flower. Oil and lemon juice, sprinkle with salt and pepper? Most veggies taste good that way or atleast that would uncover the true taste of an artichoke.
I have never baked an artichoke but because they are fairly dry it would take a long time and they might get scorched. Why don't you cut it in half, microwave it for 5 minutes or so until it is still hard, and then lay it cut side down on an oiled baking tin and bake at a fairly high temp--450 or hotter--until it is done.