I've been there a few time but in 2004 and 2005 and I went there specifically to photograph. As mentioned above it does/can get a little touristy but you can depart from it. My advice would be to stay in Yangshuo and not Guilin - its cheaper and a much better base. The hotel I always stayed in was
White Lion; it was well located (and Yangshuo is very small - can walk to anywhere) cheap and clean and it still exists. They speak English and I would just phone them up directly and book. It was also worthwhile to have them arrange a car pickup from the airport when you arrive.
Obviously things change in 9 years but what I always did after checking in was go to this bar
Buffalo Bar. It used to be run by an Australian guy so you can talk to people and understand what you should be doing. My advice would be to decide what you want to see and the time of day you want to get there. Ask at the bar about sourcing a personal guide and plan with them exactly what you want to do. If you are going there to photograph, DO NOT get involved in the multitude of group tours, you will be nothing but frustrated; stick with a personal guide.
An interesting activity I arrange one morning with my guide was to go on a bicycle ride through the country side and rice paddies. Stopped at her house for lunch then continued. Its pretty flat riding but its a long day and I wasn't used to cycling so I was very stiff at the end of the day. Pics at her house below
There's a lot you can do an see there. A week could be packed easily; 2 weeks would not be difficult to fill up either.
Some of my on line images from the area
Guilin Images