It is always ideal to have a professional photographer provide all your images. Please see the resource section of this website for references.
But if you have to stick to a budget, good, suitable photography can be found at stock photography websites. Two of my favorite websites are Istockphoto.com and bigstockphoto.com. The prices range from $2.99 to $50.00. The photography is excellent and very affordable.
Clients often provide me with pictures they have taken. Retouching these pictures and making them look their best is part of every project. Please click on the bottom two images to see retouched photography.