There are several kinds of Accelerometers. Some take a 5v power supply and supply three analog voltages proportional to the components of acceleration along the accelerometer's X, Y, and Z axes. Others sample the data (or otherwise obtain X, Y, and Z) and output a (typically ASCII) stream of data bytes. The first interface usually requires 5 wires (V+, Gnd, X, Y, Z), while the second usually has a USB connector or requires 2-3 wires (for digital signals).
Would you like us to guess the make and model of your Accelerometer? Would you like us to guess how you've wired it up to your myDAQ? How about pointing us to the "online guide" (or should we guess that, too)?
Bob Schor