It depends on the server hardware. A load average of over 1 is very high on a low-power server with a slow CPU, but very low on a very powerful server with multiple CPU cores and fast clock speeds.
A simple way to think of the load average is as a measure of the work that needs to be done compared to the work the server can do. A load average over 1 means there is more work to be done than can be done right that instant, but whether it is a problem or not, depends on how powerful the server is and how fast it is responding.
If the server is responding very quickly to your commands and serving sites with no perceptible delay, then you do not have much of a problem. That is really the ultimate measure - how long it takes to serve your sites and respond to your commands.
