Below are download links to everything you'll need to get started with typesetting definitions, theorems, proofs and reports. In general please use "white bread" LaTeX. This means you should use standard page dimensions, use standard LaTeX commands for titles, author, sectioning etc., and you should remove most all commands not actually used in the document.
After saving "theorems-proofs.tex", for example, use the tex application to process it (using LaTeX). This will produce a "theorems-proofs.pdf" and a "theorems-proofs.log" file. The .log file contains a list of how LaTeX processed the original .tex file; the .pdf files is viewable. To see it use your tex application or Acrobat Reader.
Best of Luck!!
pdh
Questions? Click here: humke@stolaf.edu