Punnett Square question (easy 10 points)?

I need some help with some punnett square problems. So if a TT (tall) plant was corssed with a tt(short plant), what percentage of the offspring would be tall? Also, if a white flowered plant was crossed with a plant that si heterozygous for the trait, what percentage of the offspring would have purple flowers. Finally, could you tell me how to setup a punnett square and tell me the answer for: A zygous round seeded plant is crossed with a zygous wrinkled seeded plant. What are the genotypes of the parents?___x___ If anybody knows a good website on punnett squares, please tell me.