What do Shakespeare's sonnets reveal about his character?
What a great question! By reading all of Shakespeare's sonnets (there are 150 or so), we are able to get into his head a bit. Most of his sonnets deal with love, so we have his opinions of women, love, marriage, and gender equality. He seems to be very romantic (take a look at Sonnet 29 especially for this), but he also has a great sense of humor (Sonnet 130 is a good example). He believed that marriage should not be taken lightly, and I am sure he would be appalled at today's divorce rates. Read Sonnet 116 for his definition of love and what marriage should be like...nothing should shake "true" love...not a better looking person, not troubles or the storms of life...it should be solid and ever-lasting like the "until death do us part" portion of the wedding vows.
Shakespeare's sonnets tell us a lot about what was going on in his head about all sorts of topics...much like his plays do.
Many of the statements in the sonnets follow poetic conventions of the period, and should not be read biographically.