I would like to design a circuit which when moves should give out a voltage. So I would like to choose an accelerometer for this application. I wish to go for single-axis accelerometer which is quite good enough for my application. I need to understand what are all the parameters that we need to understand before going for the selection.
Like most sensors, accelerometers are subject to offset and range errors as well as noise. Each of these parameters usually has a temperature dependence, too.
In addition, since you need to mathematically integrate acceleration to get velocity, there are additional considerations. A constant error in acceleration (because of offset or scale errors) results in a velocity value that drifts indefinitely with time. And the noise in acceleration results in a "random walk" of the velocity value that also grows with time.
There are various ways to deal with these real-world considerations, but it's too broad a topic to get into without knowing more about your specific application.