As stated on the landing page of Talend.com, it is the leading open source integration software provider for data driven projects. What I like about it is, of course, the fact that the open studio is absolutely FOC, and according to this comparison, it provides almost the same features as the paid Enterprise edition.
Talend by Example is a fantastic Talend resource to guide any beginner. Use it to determine which package to download, install, and start running your very first Talend job.
I started using Talend to perform file downloads from an FTP server, with the objective of automating this daily task eventually. No one around me had even heard of Talend, but luckily open source means every problem can be googled.
Although I could have completed this job using Python, Talend is just so much easier to use overall. The ability to insert java logic provides flexibility to fit your ETL needs. The canvas allow peers to understand your thinking process at a glance. Eventually, the ETL job can be scaled much faster by tapping on other Talend features.
After working on a few jobs, questions on how to make my jobs robust, sustainable, and reusable quickly come to mind. This is a good read to quickly have a sense of the best practices when designing Talend jobs.