An LLC is not the same thing as a corporation and they are taxed differently. The main difference is whether you own it directly or have shares. I don't have an LLC for photography but would if I did it more extensively or if it involved more contact with the public. I do have one for another line of business.
The main advantage of an LLC is exactly what it says - to limit your liability. If you have it set up right and someone sues you they can only go after the assets held by the LLC and not you personally.
They are relatively easy to set up but the rules and charges vary slightly by state. You can set it up yourself (I did - bought a template form on the web) or can hire someone to do it for you. Mine is in Virginia and we pay I think it is $50 per year to the state and another $300 to a law firm to serve as a registered agent. Rates in other states (e.g., CA) can be much higher. The weird thing is you don't have to set up the LLC in the same state where you live but it is best if it is where the business mostly occurs. Having a registered agent is a requirement unless you want to man a permanent address yourself. You will have to set up an operating agreement and keep track of at least one meeting per year - your registered agent might help with that part of the paperwork. You also will need to get a separate EIN for the LLC and a separate bank account in the name of the LLC is best to make sure it is completely severed from your personal assets. It is a minor hassle and takes a bit of time to set up all of that but easy to keep it going afterwards.
At tax time you do a separate filing for the LLC (due around the middle of March) and then the income (or loss) flows through to the owners who add it to their regular tax returns. If you are doing anything that involves regular contact with the public or otherwise has possibilities for liability lawsuits then I would definitely set up an LLC if you can - for relatively modest hassle it protects the rest of your assets just in case someone went after you, and they are much less likely to bother knowing the assets they could get if they won are lower. You might want to get the advice of an attorney (which I am not) if you proceed. Good luck!