Symptoms include severe itching, burning, and soreness, irritation of the vagina and/or vulva, and a whitish or whitish-gray discharge, often with a curd-like (cottage cheese) appearance. Many women mistake the symptoms of the more common bacterial vaginosis for a yeast infection. In a 2002 study published in the Journal of Obstetrics and Gynecology, only 33 percent of women who were self-treating for a yeast infection actually had a yeast infection, while most had either bacterial vaginosis or a mixed-type infection instead.

In men, symptoms include red patchy sores near the head of the penis or on the foreskin, severe itching, and/or a burning sensation. Candidiasis of the penis can also have a white discharge, although uncommon. However, having no symptoms at all is common, and usually, a more severe form of the symptoms may emerge later.

(source: Wikipedia and personal experience )

Here are some more in-depth symptoms from the Yeast Cleanser eBook (take the quiz!):
Symptoms for an acute infection are often easy to detect and treat and will come on quickly and painfully. While such infections may seem worse they are generally considered better for you in the end because of the speed and ease with which they can be treated. Symptoms include