Man this almost killed me.
http://www.emusonacid.co.uk/tutorials/
The crossfade tutorial is here. Feedback is appreciated. It's been quite difficult to do but hopefully someone will understand me!
Have a go. There's a sample to download as well. It's probably not the best example sound to use so feel free to choose your own. Don't worry though you should hear the crossfade effect clearly as long as it's a pretty longish sample (or preferably a loop).