J-Ben provides an easy-to-use kanji "flash card" mode. This can be accessed via the "Practice->Kanji" menu item. It requires that you define a kanji study list before using it.
The kanji practice mode is intended as a basic self-study tool, and does not ask you to input any answers to questions or anything similar. It will display information about a kanji with some of the information hidden from view, and it is your job to guess, either mentally or on a separate sheet of paper, what the missing information is. After doing this, you can look at the hidden fields, and you decide for yourself whether or not you remembered the character properly or not.
This is a self-graded test; you decide for each character whether you got it "Correct" or "Wrong", and the program will simply track your answers and help you study the ones you had trouble with. The program will continue to drill you through the characters you mark as "Wrong", and at the end of the test will present you with a score and a list of the characters you got wrong.
The first step in using this mode is to select which characters to test yourself on. You start by choosing how many characters you want to test, and then you pick whether to select the kanji randomly from your list or in order from a certain index of your list. The former method may be better for general review, while the latter would be good for practicing through sets of new characters in your list.
The second step is choosing the type of test. If you want to practice writing characters by hand, you will probably want to try the "writing kanji" option. However, if just reading the characters is sufficient, which may be fairly true if you only read or type Japanese, then you might be better served focusing on "reading kanji".
After clicking "Start Drill", test mode begins. While in test mode, any active dictionary searches will be cleared, and you will be unable to access the word and kanji dictionaries until you finish. The screen will display 4 textboxes containing information about the kanji: the character itself, its on-yomi (sound-based) reading, its kun-yomi (Japanese style) reading, and its meaning in English. Some of the textboxes will be covered up, depending on which test mode you chose: for "writing kanji" only the kanji character is covered by default, while for "reading kanji" everything except the kanji character is covered. You can uncover each of the textboxes simply by clicking on them, or you can uncover all of them by pressing the "Show Answer" button. (Clicking "Show Answer" in "writing kanji" mode will also show a stroke order diagram for the kanji, if present.) After reviewing each flash card, you choose whether you got it "Correct" or "Wrong", and then the program will go to the next card in your list.
After running through all of the flash cards, if you marked any of them as wrong, the program will continue to drill you through the ones you missed. At this point your score won't change; this is just extra practice and if you want you can click "Stop Test" to skip it. I recommend running through this, though. The extra review ends once you've marked each kanji as "Correct".
At the end of the test (or if you select "Stop Test"), the Test Results message box will appear. It will tell you what your score was, how much of the test you finished, and which kanji you missed, if any.