If you are trying to do an experiment to test out the effects of temperature on seed germination, you need to control for all other variables, or your experiment will not be valid. That means setting up identical containers with the same bedding material, the same moisture level, the same light level, and the same types and densities of seeds, but subjecting them to different temperatures. Light would be difficult to control in this experiment unless you excluded it entirely. I would suggest setting up three flats of seeds, covering them all tightly with aluminum foil to exclude light, and setting one in the refrigerator, one somewhere out of the way in the house (don't put it in the sun or you will have huge temperature swings in it) and one in a stable warm spot or on top of a heating pad.You also need to decide what data to gather. You can simply count sprouted seeds by visual inspection each day, or you can carefully measure the lengths of the radicals (baby roots) of each seed after a set number of days.

Also, if you are doing this experiment at home, mustard seeds are cheap and grow very quickly. You can get them in the spice section of the grocery store. Also, if you just want to work on germination, you don't even need soil; you can line containers with dampened paper towels and put the seeds right on top of them; the seeds will sprout readily, and the roots will be easy to see.

The links below may help.

I'm not sure if you are asking for suggestions regarding how to set up experiments to show the effect of temperature on plant germination or if you are asking eNotes to help you find descriptions of experiments that have already been done. I'm going to provide some suggestions.

Start by determining the hypothesis you want to test with your experiment. Do you want to measure how different temperatures effect the germination or how the length of time at a certain temperature effects the process? How many different variables of temperature or time do you want to track?

Depending on the space and temperature-controlling resources you have available, set up your seed beds, using seeds that will germinate relatively quickly. One set of seeds in a sunny window, another set in a cool basement, another set on a shelf in the refrigerator, another set placed on top of a heating pad left ON at a low temperature for the entire time of the experiment - the number of temperature conditions you could evaluate is limited only by your imagination!