Hey.
16th notes mean, that in a bar of four, there are sixteen notes. These are known as semi-quavers.
If you play each of them twice as long, you'll get eighth notes. These are quavers.
If you just play four notes in a bar, these are crotchets.
Two notes - minims. One long note - semibreve.
Remember, if you're playing in 3/4 (three beats in a bar) there are 3 crotchets in a bar, 6 eighth notes (quavers) and 12 sixteenth notes (semiquavers).
Hope that makes sense. If you want to hear 16th notes in action listen to some fast repetative grooves from Jaco Pastorius or Francis Rocco Prestia from Tower of Power.
Regards
Mike