There's really no rule for summer or winter, whatever you feel comfortable with. Usually, one tends towards fresher stuff in the heat of the summer. My fresh favorites include, among others, Dior Eau Sauvage, Guerlain Vetiver, and Mugler Cologne. I tend to dislike most modern sporty or marine fragrances, which tend to be very sharp and chemical. But that's my taste, stuff like Light Blue, Bleu de Chanel, and so on is very successful.
In general, if you are just starting, try smelling many things - so you see what you are attracted to. In addition, remember that the top of the fragrance (ie the first 15 minutes) can smell quite different from the main part (ie after 1 hr) - often companies spend money for the top, but then the body, which is what you'll smell most of the times, is different, and not as pleasant.