Here are some places to get impressive samples, captured live and on the hoof,
of what it means to prepare a TeX document, using LaTeX as your input format.

You can get all the examples you could possibly want from the following site:
(This is the world's dominant mathematics Preprint Server. That means this
is a site where researchers who have prepared papers can submit them for
anyone to see while the papers are under review for publication in the
major research journals. It's a mode of quick distribution of the latest
research work. You'll notice that almost all the documents there are
TeX-based; that's just the way it is in mathematics.)

If you pick any document, you'll see that it's available in multiple formats.
I chose one more or less at random; it gets its own web page:

Down at the bottom you'll see that you can "download the source", which
means you will download the actual LaTeX document which produced the paper.
This is an ordinary text file, probably hand-typed by one of the authors.
To speed transmission and so on, the people who run the website will send
the file in a compressed format, and a typical Unix machine would have
the de-compression utility; your mileage may vary. I have downloaded it
for you so you can see what the input file looks like: here it is:

You, the budding technical typist, can create a document like this.
Obviously you are not going to be creating anything so long or so technical;
the point of providing this example to you is to show you what the
templates look like.

If you want to see what the output should look like, take a look at this
PDF version of the paper. (Note that the PDF standard includes the provision
for making documents "clickable" like web pages; if your PDF viewer supports
this, you should be able, for example, to click on citations to be 
taken to the bibliography.)