When interested in a visual representation of structures, 
I recommend visiting a search engine such as  Yahoo
Enter the item you are interested in, into the search 
window, click on the "Images" tab, then search.

What is DNA?
Why is DNA so special?
What are genes?

DNA    deoxyribonucleic acid

DeoxyriboNucleic Acid
deoxy ribo nucleic acid
deoxy ribo nucleic acid
de oxy ribose a polymer of mononucleotides
without oxygen a 5 carbon sugar nucleotide
The 5 carbon sugar ribose without 
the -OH group on the #2 Carbon
a nucleoside       with acidic phosphates

a nitrogenous base   attached to a pentose sugar

nitrogenous bases of DNA 

purines- adenine, guanine
pyrimidines- thymine, cytosine

DNA is  polymer of nucleotides, containing the pentose sugar ribose, without oxygen on the #2 carbon.
The nucelotides within a chain are connected to each other by a chemical bond between 
the phosphate group of one nucleotide and the pentose sugar of the other. 
DNA usually exists in a double stranded form. The two chains are connected to each other by 
hydrogen bonds between the nitrogenous bases.

Each chromosome is a long double-stranded molecule of DNA.
Some sections of a chromosome are known as genes. Other parts of the chromosome
have no precisely identified function. They may be important for the timing of gene
utilization and thus the coordination and orchestration of the genome.
Each gene is a particular length of DNA which is the raw code for a protein,
or an end product RNA compound.

One protein may be a structural molecule of the body, such as collagen. Another protein
maybe a mobile molecule, such as albumin. Other proteins may be enzymes which
function in the assembly of other types of molecules of the body, such as lipids
and carbohydrates.