I have been of the understanding that Linux is relatively virus and intruder safe. How accurate is my understanding of this?
Pretty spot on.
There are no "virus" types of program that will bother you.
There are "trojan" programs around, just don't run anything you didn't get from a trustworthy place - you can always ask here first.
There *are* frequent security vulnerabilities in many network-facing services - but under Ubuntu, none of these are enabled by default. Also, as long as you run the package manager to "update" and "upgrade" regularly, the known vulnerabilities will be patched for you automatically. Generally within a few days of becoming known, Ubuntu will have a fix available.
(As usual, these statements are "99%" accurate ... nitpickers welcome :-)
-jim
