What genetic contribution does each parent give at fertilization?

Each parent contributes one haploid set of chromosomes to the zygote. In humans that means 23 chromosomes from the mother via the egg and 23 from the father via the sperm. Together they form 23 pairs (46 total) in the zygote. 

One chromosome of each pair comes from the father, the other from the mother. Additionally, the egg contributes most of the cytoplasm and organelles (including mitochondria inherited maternally); the sperm contributes centriole and paternal chromatin. Thus the zygote’s nuclear genome is half maternal, half paternal, and non-nuclear contributions are largely maternal.