[texhax] getting started, structurally

[todoke_SV1]

I've installed the MaxTeX distro it's up and running and I've enough docs to find how to write simple texts,
yet I don't know how to adequately start texing a whole lot of lecture notes in a structured way.

What I want to do is:
define the layout without going into much detail (quite condensed, little border, no huge headings but some underlinings).
then enter the notes, using only a small number of logical classifications (definition, proof, ..) and most of the text will be math.

Can you recommend a guide or packages that ease my intent?

thanks!