Sampling is not easy at all. I'd say the best thing is to get a drum beat going. You need a groove... Then go into the vinal and find a good sample to build around it. If you don't have a big beat and groove, no one will vide to it. At least in the hip hop genre.
What genre are you aiming for? Hip Hop? Drum n' Bass? Big beat? Electronic?
Cause I noticed that some of the samples were cut a certain way. If you are going for dance and Drum n' Bass, you can have samples skip and change. But, it has to be done skillfully and right. For example, FatBoy Slim.