Easy to use desktop systems such as KDE and Gnome will go a long way towards helping people from other platforms feel at home. The building and installation of open-source software is another matter. One rule of programming is that the documentation can always be improved. This is especially true with regards to educating new Linux users. A great program may go unused if few people can figure out how to get it up and running.
Introductory documentation is very important for new users, yet it is often neglected.
Good introductory info should tell the user what the program does, how to perform the installation, how to use the program once it is installed, and where to go for more detailed information. It is suprising how many projects lack some of this basic information. Project maintainers would do well to find an uninitiated person to do a test installation, such a person would likely ask questions that could ultimately be turned into better documentation. As the level and consistency of Linux documentation improves, the experiences of new users should also become better. Along those lines, the Open Documentation Summit was a pre-conference meeting to the Open Source Convention.