accelerometer filtering before board?

I am just about to set up an accelerometer to an Arduino, but read this on the Sparkfun website;

"You will need some extra hardware to convert this analog signal to a usable digital one."

I searched the forum about this but couldnt find anything. Do I need to do anything else besides just plugging the accelerometer into the analog in pins?

Nope, you don't need anything else if you're using the arduino analog pins for the accelerometer. if you were using the digital input pins, you would have to convert the analog output of the accelerometer to a digital output using something like an ADC chip.

analog pin of arduino has what you need: an internal ADC (analog to digital converter) with 10 bit precision, that's quite good

Did you buy the chip? Did you buy the breakout board? Which accelerometer?

Without that information the answers you have received are just guesses based on what people think you have.