There are (as of time of this post) two books on the market for GoldenGate and if you need to start with one, the Apress book is it (there are some good points in the Packt book, but this one is more extensive).
The book provides some very good detailed examples, especially the one dealing with how to split or parallelize an existing setup. From installation to planning for migration, the book does a great job of explaining what needs to be done when and where. There is coverage of heterogeneous replication, but it is not as extensive as the coverage for Oracle, but the main show in town for this is Oracle, so keep that in mind if you are looking at how to replicate between Teradata and MySQL.
The writing is clear and not cluttered with extraneous content. The accuracy is also quite good, minus one detail (the default port for the Manager is 7809, not 7840, as stated several times throughout the book). The editors missed Goldengate versus GoldenGate, and Weblogic versus WebLogic several times - the point of this being that you have to look somewhat hard to find mistakes, and there aren't many.
Overall, if you are new to GoldenGate, this book will provide you with a great start on getting up and running in no time at all. You can use the demo_ora_create/insert/misc SQL scripts that come with GoldenGate if you need some scripts and data to get things going.