Relation between samplingrate and frequency I am working on Fourier Transformation, and applying this for recognizing an audioclip.

I have a 9 second long audio clip of a guitar strumming an A-Minor. 
The audioclip has a sampling rate of 44100 Amplitudes per second, and a bitdepth of 16 bits.

I do a fourier Transform of the audiofile(green graph), and get a spectrum where the samples are the x-axis. I want to have frequencies along the x-axis, for being able to recognize the pitches, so I again can recognize the chord that is being played.

Instead I get samples. How can I convert this to frequency? 

Here is a photo of my spectrums, one of them zoomed in on the samples from 0 to 10 000.
you have 9 $\times$ 44100 = 396900 samples. I assume you did a single FFT and you should take the first , 198450 complex points for your plot after taking the magnitude square.  The last 198450 points out of the FFT are a mirror image of the first 198450 points so you can neglect them. The first kept  point corresponds to $f=0$ and the last kept point to $f=22050$ Hz.  which makes each bin  .1111 wide