What sort of pictures do you have? There are various techniques for getting a 3D design from an image, but they're very hands-on and require a lot of practice before you even try to work on an actual design. Seriously, don't make your final design your practice model. You'll have to learn the skills if you want to do it properly.
If you have good images (like a 360 degree set of photos around the object) then you can use something like Autodesk's 123D Catch software. It is free and it will create a 3D model based on the images you give it. Better images will produce vastly better results. With this, it's as much about photography as it is about 3D design. You'll need superb photos. It will only create the rough mould though - You'll have to go through and add extra texture and surface details by hand.
If you have blueprints (like a front design, left design, right design, up and down, etc) then you can use a 3D program like Blender or GMax (both are free) and set the images as reference images in each frame. So when you look left on the software, you'll see the left shape. You basically work by balancing the shape in all 3 dimensions to create a design which matches the images. It's time consuming and tricky, but it can be done.
If you have a few rubbish images with no real geometric properties, it becomes very tricky. Best thing to do? Hope and pray for the best and just model in 3D by guesswork and rough approximations that you can make from the images you have. A very inaccurate method, but it does work. The aforementioned Blender and GMax will do that task too.
