If you've booked your wedding venue, then it's never too early to start booking suppliers, especially your photographer. Be aware that the time of year that you're getting married will depend on the demand for your chosen supplier. May through to September will always be busiest, with lots of clients booking a year to 18 months in advance. As always, make sure you choose wisely. Get a good feel from your photographer and make sure their style suits you. When you do come to book, a holding fee or a deposit is all that is generally required to secure your date.