Ask anyone "What's a great lens to start with?" and they will probably suggest a solid 50mm Prime. Decent focal length, wide aperture, and affordable. Most Canon shooters start with a 50mm F/1.8, but here's a solid deal on the better quality Canon 50mm F/1.4. Typically listed for around $340-$399 dollars, today you can find it for just $299 via B&H when you add to cart (click here)
Canon 50mm F/1.4 Instant Rebate.