...I'm a filemaker guru, but its overkill for a simple contact manager unless you are building a custom solution to run your entire business. And while the starter solutions are good: customizing a solution properly requires a bit of knowledge if you want to do it properly. Only look at filemaker if you have bigger plans in mind. I think Filemaker is AWESOME. But I'm not sure it fits what the OP wants.
There is a huge range of solutions out there. Some of them are purpose built photography applications. Others are general purpose applications. Most have free trials so you can check them out.
You need to figure out what solution best fits your business. Start by writing down what your requirements of a system are. Figure out how you want your "everyday workflow" to work. For example: "Customer calls, I enter their details into my i-pad", if this is your workflow, then you need an application that works on an i-pad! Your list of requirements or "specs" will help you narrow down your search for the best set of tools for your business.
Allow a bit of time to do this properly. I spent a few months searching for the right solution for me: and I came up with nothing.
But thats because I'm a fussy bugger, so now I'm building my own system using the before-mentioned Filemaker.
I would look at a few of the dedicated photography solutions. Out of all the ones I evaluated ShootQ came out tops for the online solutions. Its comprehensive, coded well (there are some sites that literally don't work!) and should do most of the things that you want it to do. It has a monthly subscription charge. For an off-line solution look at Lightblue Software: they recently did a major upgrade on their product and it looks great and works well. There is a one-off licence fee, and (I think) an ongoing fee if you want to use the solution online.
But there really is a lot of stuff out there. Check out Google Apps, google "photography management software" and check those out, and try a lot of the trials. Look for something that is right for how you work. Beware of "fly by nighters" trying to cash in on the internet boom in Apps though, if the website looks dodgy and things don't seem right, then its right to trust your gut.