I do not know of any tutorials, though you might be able to find one in the board Warriorstrike linked you to.
If not, I'll be offerin' some help here. All you'd need to create a fur texture is a good art software such as Photoshop, Gimp, or Sai. Making these textures is the same as making a preset for your character. T'is the same concept, and using the UV references your my_presets folder should come with, you should easily be able to make one. The size of the canvas must always be 512 x 512 pixels though instead of it being set to RGB color, it must be set to Grayscale.
To get started, I suggest searchin' up a few wolf or lion pictures depending on which model you'd like to create a fur texture for. These can be used as refs so you can get a basic understanding on how the fur is supposed to start, look, and so on. Be sure you are paintin' on a white background, and be sure you are making good use of any fur texture brushes and blend tools to make the texture look how you want it to.
When you are finished, delete the UV reference layer if you used it and compress the entire image into one layer if that isn't already done. Save the files as a .jpeg with the names cbodyShade, cheadShade, ctailShade and so on. If you are making a feline texture, replace the 'c' with an 'f' and paste these textures into your Feralheart > Media > Textures folder. Always save the default fur textures in case you would like to revert back to them.