When you work with database systems for a longer time it is always a good idea to step back from time to time and look at "your world" from some levels up (isn't it the season for that anyway?). Now there is a book that helps you to get a good overview of not just DB2, but also MySQL. Any idea what book I am talking about?
After some years since the first edition, IBM just updated the MySQL to DB2 Conversion Guide (a so-called Redbook - no Oracle involved). What is good about the book is that they start with a high-level introduction into DB2 9.7 with its architecture and database objects and components, the available tools and utilities, and different ways of accessing the data (APIs, languages, etc.). Thereafter, they focus on MySQL and give a similar introduction. Only if you understand your source and the target platform a migration can be planned well. The rest and biggest part of the 450+ pages then deals with the necessary steps to successfully convert an existing MySQL-based application to one running on DB2.
It is something worth reading. And if MySQL is/was not your world, maybe you are interested in reading the Oracle to DB2 Conversion Guide.