Here are some links to useful pages on a range of topics. Any new summaries and how to's would be very useful, so if you have any expertise in a particular software or other skill (relevant to Astrophysics anyway, unless anyone particularly wants how to guides on other random subjects, like how to make a quick mix sponge cake)

How to design a poster

Basic Shell Commands

Plotting

Choosing and using programming languages (PDF)

Version control using SVN and CVS

Everything important about Nedit

Make a three-colour image

Dave Acreman and Eric Saunders' tutorial summaries may also be of use to others, particularly to students. This page links to their summaries.