Which seeds to sprout?

You can sprout pretty much every seeds, as long are they are not those of a poisonous plant (seeds from the tomato family must not be sprouted).
I recommend that you buy seeds in a natural food store. If you want to try different seeds, do some research on them before buying and sprouting them. Be careful and do not experiment without knowledge. There are plenty of books about sprouting out there.

I suggest to beginners to try alfalfa sprouts. They are tasty and easy to grow.

You can also sprout:
Legumes: adzuki, fenugreek, lentils, peas, garbanzo beans, soybeans, kidney beans...
Cereals: oat, wheat, corn, millet, rice, buckwheat, rye...
Nuts: sesame, almonds, sunflower...
Vegetables: carrots, broccolis, fennel, radish, parsley, onion, mustard, celery...