Plan early to give yourself plenty of time to research several different photographers. You may need to start more than a year in advance as a lot of the good ones get booked up this early.
However, don't rush the decision as the more you look at the better an idea you will have and more importantly what you like. It's quite normal to change your mind and once you know your colours, the venue for both the ceremony and the reception, then most ideas start to take shape.
Do your research and talk to several different wedding photographers and get to look at their portfolios. You'll soon get a feel for who you do and don't like and even get some ideas on pictures you never thought of or realized you could have taken. Make sure you get to see complete albums from full weddings, not just a compilation of their best images.
You don't want to hear yourself saying in the years afterwards, that you wished you'd just spent a little more on the photographs to have had the ones you really wanted.
That's why it is so important to do some research and see as many photographers as you can as you'll be amazed at how you can get just what you want that fits within your budget but be prepared to discuss closer to the 1,000 mark for a full classic album. That said, do bear in mind that less established photographers will tend to charge less for their services, but this does not mean that they are not worth considering indeed, many are very talented and will go that extra mile to ensure that they enhance their reputation with every wedding they shoot.