- A?good UI-testing framework (whether you plan to test UI)
IMHO, I recommend you to take a look at these libraries:
- TestNG (http://testng.org/): easier (and has better features) than JUnit;
- FEST-Assertions (https://github.com/alexruiz/fest-assert-2.x): It makes your assertions more fluent. I prefer using it than Hamcrest (https://github.com/hamcrest/JavaHamcrest), but it's just my personal taste;