What are the two parts of the DNA that make up the sides of the double helix?

I'm not sure I understand your question, but DNA is a huge molecule formed by two very long polynucleotide strands. They are linked together by hydrogen bonds between complimentary pairs of nitrogen bases. It looks something like a ladder. Sugar-phosphate would be like the rails of the ladder and the paired nitrogen bases would be like the steps. Hope this helps somewhat.