Once again, we want to start by saying Congratulations! You have made it through a tutorial and are progressing in your abilities to extract information from the web. At this point you should have the basics under your belt to scrape most web sites from the workbench and manage those scrapes from an external script.
From here you could continue on with any other tutorial that seems relevant to your project or curiosities. The remaining all build off of the second tutorial. The differences between them can be summed up as pertaining either to how the scrape is started or how the extracted information is processed. In some cases they will required that you have a Professional or Enterprise edition of screen-scraper.
The fourth tutorial is similar to this tutorial but as the scrape is quite a bit longer the management script is also. It is a great next step if you want to continue learning about managing scrapes from external sources.
At this point you may want to consider reading through some of the existing documentation to get more familiar with the particulars of the product. Whatever you choose, the best way to learn screen-scraper is to use it. Try it on one of your own projects!
If you don't feel comfortable with the process, we invite you to recreate the scrape using the tutorial only for reference. This can be done using only the screen-shots or review outline while you work on it. If you are still struggling you can search our forums for others like yourself and ask specific questions to the screen-scraper community.