Some of what people really need are small how to's as well as possible tips and tricks for the use of their computer to make their life easier.
First and foremost never panic. Panicking will lead to possibly more problems. The best thing to do is to take a step back and take in everything that is going on. Most of the time what comes up wants user approval for an action.
The first thing to take note of is when a popup alert comes up. They can be anything from Java, Adobe Flash, or even a program that was kicked off prior to a reboot.
"What is it that you need to look for?" Or "How do I know this is safe?" Simplest answer there is if you started the installation, the next series of pop up notifications are more than likely safe. So what you need to do is just read the message and generally if you are installing something click yes. To answer the other question on how do I know this is safe, if this is at the start of the computer, typically you are going to be prompted to install Java or Adobe Flash.
One of the best tricks out there for when a problem comes up is to take a picture of it for the technician. What we have found is that when a picture of the problem is taken, it can lead to a quicker solution. The picture or pictures that are presented can really tell what's going on. And in a lot of cases save a lot of troubleshooting.