Light behind you is a good place to start, but remember that you'll get a much nicer shot if your subject isn't straining to keep their eyes open whilst looking straight at the Sun! To deal with your shaky hand, use a tripod or - more portable - a monopod (like a tripod but with one, rather than three, legs). If you don't want to buy one of those, use whatever's nearby to support yourself - a rock, a post, a wall - as it will help you steady yourself. Also, try to relax when taking your pictures and ensure you're standing comfortably. Many people say you should opt for a 'proper' stance (feet shoulders' width apart, etc.) but I would say that you're body is more likely to relax - and not shake - if you are at your most comfortable.
Hope that helps!