We made models of DNA and learned about the steps for DNA Replication

You ought to be able to draw the ladder structure of DNA
The two bonds are hydrogen bond and phosphodiester link
Draw a nucleotide and tell me the steps of DNA replication:
1.  Strand unzips with helicase
2.  RNA primase lays down the RNA primer
3.  DNA polymerase builds the new strand in the 5' to 3' direction.  The replication of the lead strand is followed by the lag strand
4.  Ligase fills the gaps on the phospho diester links

Here is the original paper written by Watson and Crick. check it out:  DNA was discovered by Watson and Crick, Franklin and Wilkin.