First, you need a wave editing program. For example, i use Cool edit pro 2.0. SOmething along those lines that gives you alot of effects and filters....
Second, You will need two learn how to sample if you dont know already. This includes your editing of wave files, looping and processing.
Third, After all that is done you need to find a designated folder (or make one) in fruity loops to send your samples to. So then, when you open fruity it will be at your finger tips in the side panel.
Finally, throw it into fruity and play with it. I forgot to mention to find the tempo but if you use the fruity slicer it will tell you. There's alot more to it but thats the basics to get you started.. That's the way i do it, don't know how else to do it...