I decided to write this guide based on my experience with trying to get content and apps on to my Archos 5. It wasn't easy. Here are 3 things I think will help a beginner.
So, the first thing you should know is what this is. It's a QR code, and it's basically a bar code that acts as a link to a webpage. When you go looking for Android software, you're going to find these QR codes. They're going to link to either the developer's website, or a certain page in the Android Market. If you see the QR code in a (paper) magazine, you're supposed to take a picture with your Android phone and it should go to wherever the QR code leads. (My Android tablet doesn't have a camera, so I don't know.)
How to Download Software
Last week I had a conversation with a developer of an Android tablet. I asked him how to find software to download for his gadget. He suggested searching the web and "just download what you find". Um, no. I tried that. It didn't work out well.
Based on my experience, I don't think Android is designed to handle downloads from any source other than the authorized ones (app stores, device makers, etc). My Archos 5 certainly wasn't happy with apps downloaded from just anywhere. It seemed like if I installed an app from legit source, the app would run better than the same app downloaded from the web. Don't ask me why.
So, there are 2 main sources for apps: Android Market and Appslib. Android Market is a webstore of free and paid apps, was created by Google, and is only open to authorized devices (and hacked devices). The second was started by Archos, and is open to everyone. It's also free.
If you want to use the Android Market, you either have to buy an authorized phone or see if someone developed a hack for your particular device. On the other hand, you can instead find your apps through Appslib. All you need to do to use Appslib is download and install their app.
Authorized vs Unauthorized devices (or, why you can't access the Android Market)
In their infinite wisdom, Google have decided to limit access to Android Market. Only devices that Google approve of can legitimately use the Market. Fortunately, if you have a popular device then someone has probably already written a hack so it can use the Market without Google's approval. The best way to find the hack you need is to google "my device android market hack".
I know there is a hack for my Archos 5, but I don't see a reason to install it. I will only install free apps, and every free app I want is available in Appslib as well as the Android Market.