I just wanted to point to this article on the ESXi Chronicles blog about a free training and free book on ESXi. I actually wrote an article about the book a while back and it is most definitely worth the effort of doing the training and survey!
You might wonder how much a person can write about ESXi, but Dave managed to fill up rough 490 pages. These pages contain solid and detailed information about the ESXi architecture but also for instance on how to implement or secure an ESXi environment. The book has 8 chapters which will take you through the installation and migration step by step but also will prepare you for operating ESXi based environments. On top of that Dave not only discusses the rCLI/vMA but also PowerCLI and it contains some really useful sample scripts.
You can find more details about the training and the book in this ESXi Chronicles article.