Start off by purchasing a digital SLR with a “cropped” sensor
Entry level and prosumer level digital SLRs typically have a smaller sensor than “full frame” cameras. These allow the cameras to be smaller, lighter, and more affordable. The tradeoff is usually quality and low light performance and it will affect focal length of lenses you choose for specific photographs. It is relatively difficult to tell the difference in quality, so when it comes to the price savings, a smaller sensor is a great choice for folks just starting out.