Maybe we should start with what kind of computer you have and OS and work from there bakabaka1. I see that most people render at 1000 x 1000 but I useally go for 800 x 600 till i find the render I want. I start out small and work my way up till i like what i have then render at 1600 x 1200 . The DPI that was mention really only has to do if your going to be printing the render. The profesional looking part is the lighting and well worth your time to learn about it by reading what people post about it and the tutorials.