You will find thousands of Yagi and dipole antenna articles on the Internet. Search for "yagi antenna" or "dipole antenna" using Google.
You can also create your own antenna plots:
4nec2 is a completely free Nec2, Nec4 and windows based tool for creating, viewing, optimizing and checking 2D and 3D style antenna geometry structures and generate, display and/or compare near/far-field radiation patterns for both the starting and experienced antenna modeler. Download from here:
**broken link removed**