Xelofino posted a very nice basic tutorial in the german forum http://www.simutrans-forum.de/forum/thread.php?postid=70166 (http://www.simutrans-forum.de/forum/thread.php?postid=70166).
I think this is a good way to get started with playing simutrans, so I tried my best to translate it into English:
http://simutrans-germany.com/files/upload/Simutrans_Tutorial_1.1_xelo_en.sve (http://simutrans-germany.com/files/upload/Simutrans_Tutorial_1.1_xelo_en.sve)
If you have any suggestions (I'm not an English native speaker), please feel free to post them here. Please be picky, as this might be the source for other translations.
This tutorial should work with all pak sets. Use pak64 if in doubt.
Xelofino plans to make more tutorials in this style.
Edit: new version with 2 small bugs fixed