A quite a few tomato plants have come up now, along with a few sweat peas. My other tomatoes haven't come up yet but I am not suprised because my first tomatoes took a while to come up.
Sometimes plants need drainage to do well. From what I understand, if you have a flat layer of clay below your plants then when you water them the water will collect down at the bottom and you plants won't do well. So (I think) the solution is to lay a pipe or lay rocks in the bottom of the bed and fluff up the soil. Make sure the rocks or pipes are inclined in the direction you want it to go.
Hotbeds and coldframes are boxes in which you would put plants that you want to prepare for the great outdoors. A hotbed has an electric wire running through it to keep the plants warm. However, a coldframe does not have this ability. For a coldframe you have to pile dirt or mulch around it. On both of them however when it gets hot you a have to open it a little ways. The hotter it is outside, more open it should be.