Having played Battleheart Legacy ($4.99/Universal for iPhone and iPad) for nearly a month now, let me share some of the tips and tricks I learned.
For a more extensive walkthrough, there are plenty of excellent and in-depth resources out there, such as in the Touch Arcade forum, but I hope my own experience will help you out as a starting player. (Check out the review/guide to Battleheart Legacy on appSIZED here)