Well, unfortunately "instructional" Mods are not that readily available, and they'd be tracker-specific. What I'd do, if I were studying for the first time is this:
First, I'd figure out about tracks, notes, samples, Patterns and pattern lists, how they interact with one another. basically you select a sample. You use that sample and place notes into a pattern. Once you run out of room, start a new pattern. then, you piece together your order, by putting your patterns into the pattern list. Re-use is totally acceptable, but overusing can make your song boring and repetitive.
Check out
This Article I wrote a few years back, which tries to teach the process of tracking, and be as tracker-agnostic as possible...
