Update README

README.md

 # Git introduction course
 
-This course aims at everyone who works in the Bioinformatics field. We cover a
-*version control system* named *Git*. This system is widely used by software
-developers, but can also be used for project management. By keeping track of
-all versions, history, etc. collaboration with colleagues is easy and your
-analysis will be reproducible.
-
-The presentations are made in *LaTeX*, for the template and stylesheet, go
-[here](https://humgenprojects.lumc.nl/svn/presentation/trunk/).
+The Git introduction course aims at everyone who works in the Bioinformatics
+field. We cover a *version control system* named *Git*. This system is widely
+used by software developers, but can also be used for project management. By
+keeping track of all versions, history, etc. collaboration with colleagues is
+easy and your analysis will be reproducible.
+
+You can find the
+[course website on our wiki](https://humgenprojects.lumc.nl/trac/humgenprojects/wiki/git). This
+repository contains lectures and practicals, written in LaTeX.
+
+## Organisation
+
+There is one submodule on which this repository depends.
+
+- **[presentation](https://git.lumc.nl/j.f.j.laros/presentation)** template
+    for presentations in LaTeX.
+
+The **website** directory is for storing the compiled presentations,
+handouts and program. A *Trac wiki markup* file contains the website
+content. Uploading, updating and adding attachments can be done easily with
+the [tracwiki](https://pypi.python.org/pypi/tracwiki) program.
+
+## Usage
+
+After cloning this repository, fetch the data from the submodule by issuing
+the following two commands:
+
+    git submodule init
+    git submodule update
+
+([More on Git submodules](http://git-scm.com/book/en/Git-Tools-Submodules))
+
+A new presentation can be added like this:
+
+    cd presentation
+    bash mkpres.sh ../mypresentation